Yes absolutely he could do so if he did so to an older version pending a few caveats. Their weights were the same... Johnson was his Reno weight and not smaller because we're using a 26 year old Jeffries. Second, assuming Jeffries, or whoever, stayed in shape and trained at 35 for a fight like he did at 26. Third, in isolation is what we're talking about here. Fatigue and stamina play a role in your strength. So at his older age, he's going to tire sooner, and thus not have the strength he did in the early rounds. However, we're not talking about trying to move Johnson while being tired old vs. the younger fresher version trying. We're talking in isolation here, and yes, Johnson would have just an easy a time moving either version just the same with the above being static. As I stated, I think strength is one of the last things to go. Just look at the World's Strongest Man Competition. The winners haven't been dominated by 20 year olds, in fact, I would at most winners were over 30. Which is the point, as long as you remain active and are training, you're not going to be noticeably weaker at 35 compared to 25 imo.