I remember Michkov and Voronov both commenting on the fact that for the 1st time Fedor wasn't serious with his fight prep prior to the AA fight ( just a few weeks while filming some BS telefilm in thailand ) ..
DIdn't do strength and conditionning for years either ( there is an old interview where Fedor himself talks about it ) apart from some dips/pullups/situps.. to "focus on technique "
Also I remember his right hand injury affected his grip strength alot on his own admittance..
It looked like he resorted on " God's will bar brawling " around the time he started to fight in StrikeForce.
Once he became a religious zealot he was inclined to bring up " God's WIll " all the time in pre fight pressers etc, and it looked like he threw any kind of gameplan by the windows..
Also could be linked to some nagging injuries/wear and tears we don't know about but this is speculation.
But I will say this too , in my opinion he wasn't enough physically fit to use his oldschool grappling heavy style after the Sylvia fight.
Dude struggled with Rogers on the ground, was outstrengthed a lot by BF, and held against the cage by Hendo.
I personnally struggle to imagine Pride Fedor being held by Hendo, even a TRT'ed to the max one...
Both his strength and power noticeably went downhill around the time he was 32-33, which is kind of a natural decline, but it was fastened by the fact that he didn't do S&C training, and worsened by the fact that these were the main features his fight style relied on...
Interesting - I've always wondered why he stopped grappling and turned into a brawler. I knew about his hand injuries, but he kept throwing the same punches and kept breaking the same hand. He was also pulling off submissions not long after his hand would heal, so I dunno if his grip strength is really a sufficient explanation.
BTW - you don't always have to be stronger than your opponent to pull off a submission - technique counts for just as much, if not more.