You're right, debilitated Saturn is still Saturn... but my assessment is that debilitated Saturn is not fully operational and has a much more difficult time "starting." Those of the Libra, Cap, Aqua Saturn variety come equipped with the essentials to just start and go.
When I say that Saturn is the moral foundation (and that's the core of our existence), I'm really being serious. There is no replacement for foundation. That's it. It's bare bones essential. If there are kinks, cracks, gaps, holes, etc. in the foundation and it goes ignored, or worse, denied attention, the foundation will crumble and that will be the day of reckoning.
If Saturn was to speak, I'm pretty sure he'd say something like, "Just because you don't believe in reality doesn't mean reality doesn't believe in you." In another words, you can delay reality, but eventually you will have to face it. That's what I mean precisely when I said that debilitated Saturn (Cancer, Leo, Aries) have built in fear of objectivity because they are not operating the way Saturn is supposed to operate. Saturn does represent fear but Saturnine fear operates differently than other kinds of fear. Saturnine fear is different because it not linked to the ego but rather it's linked to something more concrete- the goal of survival. Saturn fears the unknown. In order for Saturn to build a defense and combat against fear of the unknown, he turns around and uses that same fear to motivate himself to fortify with what is known/factual/real. That's what's called understanding limitations and working with what you know. Saturn utilizes and practice what works. Bottom line is, he is basically concerned with 2 points- 1. what works 2. remember what doesn't work to prevent wasting time in the future. Without foundation, nothing would exist. That's why Saturn is much more powerful.
What I described above, those that come into "the game" (as I call it) aka life, with Libra, Cap, or Aqua Saturn already know that life is unfair, it never was fair, and it will never be fair, but working with what you have and maximizing it is the most reasonable, feasible, and realistic goal (consciousness). Basically, they already got over the hard part. Those that come into the game with debilitated Saturn are devoid of that piece of common sense and take a lot longer to come to that realization. The longer it takes to understand and practice the most basic of Saturn maxim, the inevitable will continue to be denied and will expand Saturn's fear. The longer Saturn builds up fear, the greater increase of damage is placed on the foundation and if too much damage goes unaddressed, the foundation will not withstand. I think when that manifests, it's called, "moral bankruptcy" or "moral devastation."
Mars is very important... and is only 2nd to the Sun in ego. And when I say 2nd, I mean it's a very close 2nd...like a hair away 2nd. If the Sun is debilitated, but the Mars is at least essentially dignified, it balances out some of the damages from debilitated Sun. However, if Saturn is debilitated, he is unable to elevate any of the other planets' debilities. I still maintain that an exalted or domicile Saturn has the power to elevate debilities from other planets but I don't think any other planets dignities/exaltations can combat against Saturn's debilities. If Saturn is exalted or domicile, he is operating on maximum capacity (and part of that is reserving, restricting, restraining, rejecting) and is aware enough to pick up the slack from the other planets that may be lacking. Saturn is more powerful than all the other planets combined because he is representative of moral and rational foundation. Life's backbone is Saturn (why he rules the spine), we survive, live, and thrive based upon reason. The fact that we make decisions (decision process) is rooted in reason. We aren't instinctual creatures and feelings are not facts and do not reflect reality (that's why Saturn hates the Moon/Cancer). We created society, laws, structures- all that is ruled by Saturn. Sure, Saturn shall always be Saturn, but so will society, laws, and structures. The question is, do you want one that works optimally or do you want a fixer upper that may not even get fixed?
I'll use me as an example. Although I have debilitated Taurus Mars, my exalted Libra Saturn trines it and thus, Saturn restricts a lot of Taurus Mars debilities (laziness, being boring, etc.) but expands on some of the finer qualities that Taurus Mars has such as determination, dedication, and loyalty. I don't identify with any of the description of Taurus Mars except for liking nice things in life... but that's Earth Mars in general. My Mars is so heavily modified that it does not even operate on a recognizable level that could be identified as Taurus. And like the chart in question, my Mars is the only Earth planet in my chart and it's in the Western hemisphere. But unlike the chart in question, the person has debilitated Saturn opposite exalted Mars and I have (the reverse) exalted Saturn trine debilitated Mars. I bring this up because I want to illustrate for MilkywayGirl the striking difference.
I have Gemini Sun which is peregrine but it gets a trine from exalted Saturn. Now, I know that Gemini Sun people are crazy- say and do crazy things no matter what is in their chart, and I'm really no different, but because my Saturn is exalted, I don't tend to get in trouble with my craziness because I know when to dial it back. I will test others but I don't push anyone over the edge and I am very conscious of how I can effect others (for better or worse). I know my limits and I know how to gauge other people's limits.
I love Aquas, but they can be very psycho and too fervent and hellbent passionate on some of the most misguided ideologies possible.
I have a high school friend who's Aqua Sun and Mars trine Libra Saturn (she's a few months older than me) but she's not a typical crazy Aqua (as a matter of fact, I've met all the Aqua born with Libra Saturn in my high school classs and none of them were the typical psycho Aquas). She's very morally grounded and tries to be careful with others. When she needs help, she never asks for "free" but will offer to pay or do something in exchange. She doesn't take advantage of others whenever she's in a position of power. We argued back in high school and I shut her out but she was the one that contacted me during our Saturn's return (like 12 years after the argument) to bury the hatchet and to apologize to me.
I was friends with several Libra Sun conjunct Libra Saturn classmates and they were always annoyingly hounding me to go to church with them when everyone knew that I was (and still am) a strict atheist. They weren't doing that to say that my soul needed saving or whatever. They just felt that I'm a very moral person and wanted me to be around other people of strong moral fiber. They were looking out for me, which I appreciated but I'm definitely, not going to believe in something that I don't. And yet, we always stayed on good terms.
I've had a lot of Cancer Sun people in my high school class who have Sun square Libra Saturn and even they contacted me during our Saturn's return to apologize to me for being "unfair and mean" towards me and it "was no excuse to treat" me poorly back then when I was "always fair towards" them.
My point to all those examples is that I really do think that when Saturn is well placed, any aspect it makes to Sun and Mars, even the difficult aspects, actually strengthen morality foundations of the person. I did not want to give false hopes to MilkywayGirl, nor anyone when I read charts and see debilitated Saturn making difficult aspects to Sun and/or Mars. Yes, it's possible that anyone can "change" but the change will originate from 1. the conscious desire to change 2. recognition of flaws that needs to be changed. That chart showed me not one iota of desiring change nor being aware of any personal flaws that needs to be changed, but of a domineering person who wants to control his external world and everyone orbiting around it. I cannot lie based upon what I saw.