I was playing games on DOS before you were born, probably.
and your numbers are a bit off: Soldier, Engineer, Sandvich, Sniper and Heavy all have 15M views or less.
The most interesting one here is Heavy: he has 12M views. Wow, that's a lot more than Banjo!
But Heavy was THE first Meet The video and that was 10 (ten) years ago. That averages to 1.2M views a year.
Banjo's trailer has been out for 2 months and has 2.1M views. Another 1.3 million views on the GameExplain upload.
You gotta face it son, Heavy won't excite the world, not like Banjo did. Banjo was in a lot of peoples childhoods, and being a former nintendo property there's a lot of overlap with the Smash crowd.
Who knows how varied the TF2 sphere overlaps with Smash; obviously both you and I are in both, and I'm sure a lot of people here on /v/ are too, but to rival, even approach Banjo's splash? Not fucking likely, pal.