Funnily enough, out of the recent QBs the one that reminds me most of Tua the most would be Russell Wilson. The key difference is to me is the Hawks had decent coaching group who were fully behind him from the start of his rookie year, supported him with a great OL and rushing game to go with their suffocating defense... they went to back to back Superbowls, winning one.
Now that's not in the group of what I call the truly elite echelon of QBs (Rodgers, Brady, Peyton, and maybe Brees) who can seem to make the most ordinary of wideouts look like superstars when they join their squad. But it says to me Tua does possibly have the tools to win - provided he has the necessary support. To date we haven't given him anything remotely resembling that.
There have been lots of questions about the quality of the pass blocking of Wilson's offensive lines over the years. He's been pretty regularly regarded as a QB whose mobility and evasion of pressure has surmounted the quality of his offensive lines.
I would say the biggest difference between Wilson and Tua right now is that while both show good ability to evade pressure, Wilson has shown far more ability to throw downfield laser beams that generate big plays. Tua may have that ability as well and it may be undermined by other factors, or he may not. We simply need a bigger sample size with Tua.