That is just so unecessary to say my favourite character isn't a copy of some popular or inspired character design. I mean, please FF7 is 1997 while RWBY is like early 2010s, if there isn't some kind of references of creating RWBY cast based on some characters, I'm saying you're lying.
This is from TvTropes, so takes it as a grain of salt.
I'll confess, I don't watch any Monty Oum's stuff beside RWBY. I appreciate him pursuing his career with his passion. Saying Tifa not having a tiny bit of design inspiration on Yang is mental gymastic to me. Especially when Monty put his waifus in a "My dad is better than your dad" attitude kind of show.
About female "monk" fighting style, I'm pretty sure Tifa is the most popular one. It's inevitable when comparison with her, or using her as a reference. To be fair, that's how most people to describe stuff and I hate that kind of comparison description all thanks to Overwatch. And then with the Death Battle thing, it's almost like they are boasting some kind of comparison.
Example of hand to hand combat female characters: An Korean MMORPG game called DFO (released in 2005), they have
female fighter as one of original classes,
oh I'm 100% sure her design isn't inspired by Tifa at all.
Next Blazblue (first game was released in 2008 ), we have
Makoto, almost similar colour tone and fighting style to the female fighter above.
Not on design, but
Makoto from Persona 5 also have hand to hand combat style.
In short, I mean having originality is almost non-existent. But that doesn't mean it's a bad thing, it's how you create, portray thing you love and put it with your own "unique touch" in it.