Through many years of watching pro wrestling, I've never liked handicap matches.....and this idea by the OP is an extension of that one. In the 80's, a superstar taking on two jobbers never amounted to an interesting match, largely because we knew in advance the only reason the contest was being staged was to prove the indestructibility of the guy who was alone. The two opponents rarely got in any offense; forget the idea of them winning the stupid match.
In the 90's and later, handicap matches at least looked slightly more believable because the two guys were allowed to create some problems for the one. Yeah, they still always lost, but at least we were treated to some of what really happens when two people gang up on one.
With Ryback, of course, the pendulum swung back to what we used to see in the 80's. He'd fight two wimps on loan from an independent federation and clothesline 'em to death until the inevitable, back-breaking finish. The spectacle grew tiresome very quickly, didn't it?
So, the idea of handicap matches becoming a staple of the tag team division, with individuals competing against a single guy, doesn't sound appealing. Aside from someone like Ryback, who does it with sheer power; the idea of a John Cena or CM Punk outwitting and out-speeding two opponents might be fun for a match or two, but WWE wants it's product to look realistic, right? Having the single guy continually emerging victorious would mess with that policy.....big time. Having him hold the tag team title would be downright offensive.