Why does Sherry Birkin and Jake Muller(Wesker) make a good team?
This is why:
So Sherry Birkin is 26 and Jake is 20. For Shake fans, they believe that 'age doesn't matter'. (I'm a huge fan of Jake and Sherry) And we wanted them to be together, actually it's too obvious that they have feelings for each other. They just don't put it to the next level despite of their mission to save the world.
Stick to the topic, they make a good team because they have a lot of similarities, therefore a lot of differences.
Blood and Relatives
[First], Their fathers are great friends before, 'team mates' as well, but we didn't liked the ending of William and Albert. Somehow we wanted our Super girl and Wesker jr. both make it until the end. (What I mean is they'll still work together as a team and lovers) Both of their fathers gave all their attention to their work, which Sherry (and somehow Jake) didn't feel their fathers' affection for them. Both of their mothers' died, Annette Birkin and Ms. Muller (The mother's name is not specified) but Sherry and Jake loved them so much.[Second], despite the fact that both of their fathers are workaholic, it has an impact to their blood. They used it to enhance the project they're making. Especially William, turning him into some kind of monster and cannot be indentified due to the fact he's dying. Sherry was infected too. But Annette, her mother, would never wanted her to be like that. She gave Leon and Claire the instructions for the antidote and succesfully administrating the vaccine for Sherry, which makes her an anti-body for the said virus. And look! Jake has the anti-bodies too! Different viruses, cured by them. ((recently I made a fanfic about Jake and Sherry's next chapter of life; having a daugther named Shannon, has a blood of a mutated Birkin and a blood of a Wesker. I hesitated to publish it in public, a lack of confidence I guess. Yet i'm still in the progress of finishing it.))
Actually I was really hoping that Capcom intentionally made it in purpose. (The fact that William and Wesker are great friends/collegues before, had a child that can save the world,and ends up by pairing them. Aw. Sweet.)
When it comes to personalities, they have differences, of course. Sherry is sweet, we all used to witness her in [Resident Evil 2]. She's optimistic and independent, though her parents are working, she have to take care of herself and she is determined which contributed her to her early maturity. Jake, self-centered, trusting only in the power of money even it's no use to him because his mother died before he could make money for his mother's medical expenses. He hated his father, not like Sherry who still loves her parents even though they have no time for her.