Ooh, sounds interesting. my dream team huh? hmm....
Team Leader - Chrom (Fire emblem Awakening) He's about as leadery as it gets
Weapons Expert - The Heavy Weapons Guy (Team Fortress 2) I mean, he's even got 'weapons' in his name
Muscle - Iron Tager (Blazblue) Have you seen this guy? he's 90% muscle. Though I was also considering Zangief from Street Fighter, a comrade for Heavy Weapons, da?
Lone Wolf - Shadow (Sonic the Hedgehog) I honestly couldn't think of any others off the top of my head, and couldn't find a good list of comparison on tvtropes.
Stealth Expert - The Stealth Elf (Skylanders) Once again, her title says it all. Also the fact that she can turn invisible indefinitely and spawn ghost blades. Don't Judge me.
Jack of all trades- Yu Narukami (Persona 4) I chose him because, through Personas, he can literally be anything. Magic Damage, Physical Fighter, Ailment Inflicter, Buffer, Healer, any and all. Not only that, but he'd make a good backup leader incase Chrom get's permadeathed.
I'd say that's a pretty good and varied team right there. Too bad the only place a crossover like this could exist is in the most terrible of fanfictions