Change the Speed Ninja Master's Pokemon in Some Way

[Dragonstrike]

I don't think they are necessarily asking for it to be "easier", but instead more balanced. Inflagetah can seem pretty unbalanced when it's using Priority moves. Tiko's Inflagetah in the Amatree gym is the only Pokemon in any gym that's given me any issue whatsoever.

That's essentially what I'm asking for, yes.  The time it takes is another factor, and someone on the subreddit did mention that the punching bag is faster.  However, it's only faster if you're only training one pokemon in that stat.  If you somehow have many exp shares and want to train more than one pokemon at the same time, the battles will be far more time efficient than training each one up individually with the punching bag, particularly considering pokerus will actually do its job in the battles.

And the attention needed for both is another factor.  The difference between the two isn't major on this front, but the battles have a slight edge in how little attention you can pay to what's going on as long as you cleanly OTK everything and heal up at the pokemon center when needed (which is preferably not after every single or every other battle).