It seems pard's hand should be easy to peg. He didn't open 2
♦, so he either has 6 ugly diamonds or 5 fair ones. You didn't mention support doubles, but it sounds like you don't play them; even then he doesn't have 3 hearts. He probably doesn't have 4 spades either. And, he doesn't have 4 good clubs; else he passes the double. And he doesn't have a flat 10-12.
So, likely patterns are: 3=2=5=3 (with 13-15), 3=1=6=3 or 2=2=6=3. I'm more inclined to place him with the 1st type.
This is a funny hand. If pard has
♣Kxx (Hopefully LHO doesn't find an inspired lead of the Q from AQT9x!) or
♣Axx, I want to play NT from my side. If pard doesn't have a fair club stop, we aren't making anything close to 5
♦.
OK, I hope I'd have the guts to try this at the table, but I'm bidding
3N playing pard for something like: QJx, xx, AQJxx, Kxx. ANd I'm fully prepared to offer an apology if it turns out silly.