Themis,
Your lawyer is 2nd house when your 7th house is busy ruling your opponent. Only then is the lawyer 2nd-house as "your support". Similarly, your opponent's lawyer will be the turned 2nd from the 7th (the radical 8th).
The lawyer is 7th -house when the horary is about that lawyer with no opponants involved in the horary. It's like "how competnat is my lawyer?", "Is my lawyer scamming me on the fees?" or "Should I hire this particular lawyer?" - those are 7th-house lawyers. But in a horary when and opponent is involved, like "which one of us will win the lawsuit?" you may use your 2nd house to see how your lawyer appears in the chart.
I suppose astrologers can be treated the same way although I don't think you'll find many situations where you can use the 2nd house to rule your astrologer unless they are on your side in an astrology contest involving another astrology rival
By the way, here's a tip. I know it's off topic, but I thought I'd mention it. In a lawsuit chart, you are the 1st, your lawyer and everyone on your side are 2nd house, opponent 7th, their lawyer and other supporters are 8th-house, the judge and jury are 10th and the verdict is 4th. Some people would assign the 1st to whoever side started the lawsuit whether ther are the querent or not though which would make the querent 7th in such case (I don't know if that's correct though; I only do this when it's an event chart, not a horary).