If he lost, that means he fought tough competition. Which means he made the perfect decision instead of fighting cans (if he signed elsewhere).
There's a lot of factors one needs to take into consideration if one's making What-If scenarios of historical revisionism. I mean, Overeem was a DREAM fighter who only came to Strikeforce because SF and DREAM made a copromotion/cross-over deal. Since Zuffa doesn't co-promote, you wouldn't have seen him cross over (and face Fedor). Antonio Silva too would still be in Sengoku, since he switched to SF during the HW WGP, which itself would not have happened if Fedor (and Overeem, who was K-1/Dream champ) didn't cross-over.
There's a lot of factors one needs to take into consideration if one's making What-If scenarios of historical revisionism. I mean, Overeem was a DREAM fighter who only came to Strikeforce because SF and DREAM made a copromotion/cross-over deal. Since Zuffa doesn't co-promote, you wouldn't have seen him cross over (and face Fedor). Antonio Silva too would still be in Sengoku, since he switched to SF during the HW WGP, which itself would not have happened if Fedor (and Overeem, who was K-1/Dream champ) didn't cross-over.