As much as I love Claire, when have we seen her since then? Her role in Degeneration was so small it was insulting and she hasn't really done anything in the bio-terrorism fight since then, has she? As for Alfred and Alexia, I think Wesker's very presence would have thwarted their plans, especially since he didn't want them to succeed, he just wanted the T-Veronica virus; Alexia wouldn't want him to have it and so a fight between two relatively stable tyrants ensues.
Who would have won, I wonder? Or would they have simply cancelled each other out?
And what of Chris?
Would he have lost the will to fight after his Sister was murdered?
Would he be the same miserable and angry guy he is in RE6?
Or would he have simply given up on justice?
The possiblilities are endless here.
But that doesn't change the fact that out of all the heroes Leon was the first to get his foot in to the government and used those ties in order to help chris and others out in the fight against Umbrella.
There is no telling how many times those very same connections have helped out Chris and others.
After all, we heard of a "Kennedy Report" in RE5 which means that Leon has been in close contact and keep Chris and the BSAA informed about new bio threats in the world.
And where did you get the idea that Wesker did not want her to succeed in her plan?
The only thing I saw from him was the need to get the T Veronica virus by any means necessary.
For all we know if it wasn't for Chris coming Wesker most likely would have went to find other means of retrieving the virus instead of fighting Alexia.
After all, It did not seem as if he was having a easy time getting her to come with him in the first place.
He could have stumbled across her father's corpse and taken it and left her to fulfill her plan for all we know.
