Can Tiger use his Chi Pulse? If he can I think that'd destroy enough of Mad Dog's innards that Chen could wear him down.
If not, Mad Dog eats him alive. Rama and Andi together could barely touch him and even with a light bulb shard jammed in his neck and losing liters of blood by the second, he was still getting the better of them.
dunno, man, Tiger was no slouch in terms of damage soak or physical stats. He took shots from people stronger than anyone Mad Dog faced and kept going and also managed to put down a guy (the hung gar fighter) who displayed better durability than Rama.
i think it's closer than you're making it out to be. There's also the fact that Rama went through hell before getting to Mad Dog. Based on feats from the sequel, a Fresh Rama would've been his equal or close to it.
dude tanks shots that put bigger guys down.