^Burungeru doesn't really want Roobushin burned, though, and unless I'm mistaken it uses Will-o-Wisp for that purpose. Roobushin is one of the best Guts Pokemon in the game. It really eclipses Iron Fist.
Roar and Bounce aside, I must admit that Gyarados isn't the best Roobushin check, due to Stone Edge. Most sets that I have seen, paradoxically, run Payback, and lose that matchup. Gyarados and Salamence are just examples I chose to explain why Roobushin shouldn't tank through a whole team.
You argument is sound, and reiterates my assertion that Roobushin isn't a one Pokemon team.
Edit: I'd just like to point out that Adamant Machamp with Max HP and Special Defense has better Special Bulk (251SpDef vs 269) than Careful Roobushin and more Attack (316 vs 325) to boot. Machamp could probably still afford to invest in Attack without losing too much. Add Rest and Bulk Up, and it's a more reliable Bulk Upper than Roobushin, really lacking only Mach Punch. Dynamic Punch is as devastating as ever, and Stone Edge covers fliers. Now that's hard to beat.
Burungeru doesn't always use WoW, but almost all of them carry Boiling Water which has a decent 30% chance of burning. So currently, either they think you're using Iron Fist and they burn you on purpose with WoW, or they just get unlucky trying to kill you with Boiling Water. It and Nattorei, two extremely popular walls are great set up fodder for Roopushin. Roopushin's speed makes Gyro Ball pathetic in power which makes it rely on Power Whip, which after a Bulk Up does very little. Guts version doesn't even mind being paralyzed, although burn is preferred.Machamp might be a bit better in certain stats but it's the difference in movepool that is the dealbreaker for me. Machamp doesn't get Drain Punch or Mach Punch (Bullet Punch instead). It can't use Dynamic Punch with Guts. It would make a decent sleep talker but you'd only have one attack move with Bulk Up, or two without. Neither is very appealing.By all means though, give him a try and tell me how your experiences go, as I'm very curious. At best they may be interchangeable for bulky tanks, but I still favor Roopushin.