Don't be put off by the asymmetric formations, although they can be the hardest to beat.
Up against 3 ST and an AMC you already know you need at least a DMC + 3 or 4 defenders. He only has 1 MC so effectively any 2 MC or 3MC would kill him easily. You also don't want to be playing an AMC so AML/AMR will exploit his weak spots.
I have 2 to suggest. 3-5-2 v formation... or 3N-1-3N-2W-1. But I would rather go with the first one,
4-5-1 v sucks against 3 striker formations so don't try it.