Hope you dont mind me adding to the discussion here from an outside perspective, obviously i dont know your players skills.
Look at your SFs rating vs his, 9.5 vs 14.0. Thats not a good mismatch. Then look at the scoring per 100 shots, your SF spot is 64.9. To me, that tells me that his SF had bloody good defence in relation to your PFs scoring ability, and that for an inside iso offense, your PF playing at SF wasnt a good option to go to.
Then look at your PG, who ranked 11.5, and their PG who rated 7.5, and your guy had 107pts per 100 shots. IS there a chance that the inside isolation that your coach found most effective was your mismatch at PG? Id say their PG had a low ID rating and it was the best option your coach found.
Id say if you wanted an iso mismatch, perhaps the guy you played at PF might have played a good game on their C.