Look at their current records in the ufc, they are terrible lol except for werdum who suffered one loss.
Strikeforce did have some great HWs but only one got the Gold and he held it for what 3 minutes ring time?
There's so many holes in this argument, it's hard to know where to begin.
-Stipe wasn't even in the UFC at the time SF got bought out. His wins over SF fighters are completeLy irrelevant to the subject. ----The top names in the UFC when SF was alive are the only relevant names: Cain, JDS, Brock, Mir, Nelson, etc have all been beaten by SF fighters
-On a similar note, SF got bought out 6 years ago. Most of its top fighters are now 40. Judging fighters by how they perform in the twilight of their career's is a pretty dumb measuring stick to eval their overall success as fighters
-In spite of that, several SF HW's had successful UFC runs post-SF
-Werdum: beat Cain, Browne 2x, Nelson, Hunt
-Reem: beat Brock, JDS, etc
-Arlovski: 5 fight win streak immediately
-Cormier: didn't lose at hw; went on to beat every lhw except Jones
-Cain held the division up for several years, and 1-2 against SF fighters
-Etc, etc, etc.