Oddly enough, when I switch to a different formation, my "bogie" teams suddenly change!?

I used a 3-5-2 originally, two DH and 3 OH, doing perfectly fine, with my main "bogie" team being Roma. I bought some new players for my next season and got rid of some as well. Playing the 3-5-2 suddenly became ineffective. I then turned to the 4-4-2, diamond middle with SBs on constant attack. My tough bogie teams changed. Strange stuff.

Anyone have any helpful insight on this topic? I was just curious since I noticed a pretty big change...

Cheers