Today I played against a 38.2 (I'm a 25.5) in Cup. His lineup was kinda like yours:
DR DC DC DC DL
DMC
MC
AMC AMC
ST

It's not illegal, but it is a lame lineup, I had 60% of possession in the whole first half and I'm way worse then him, just because my wingers were basically unmarked. I won cause two of his player got injured and the ST got expelled so I finally managed to score three goals.
Still, I think his lineup wasn't illegal because he had two amc, but should be in any other case, especially matena's one.

Maybe your opponents set their lineup with players out of role, like a dc used as a striker. Last league there were like five teams like that, chances are you met a lot more.