Korrina:
Hawlucha VS Machoke, Hawlucha wins
Froakie VS Mienfoo, Froakie wins
Hawlucha VS Lucario, Lucario wins
Froakie VS M-Lucario, Froakie wins
Why is Ash only using two Pokemon while Korrina is using three? Also, it's a Fighting-type gym, so Fletchlinder should get some sort of involvement. It didn't do too well in the first two gyms (although I understand Ash's logic VS Grant) and needs some good battles here. I'd prefer something more like this:
Pikachu VS Mienfoo (Pikachu)
Pikachu VS Machoke (Machoke)
Fletchlinder VS Machoke (Fletchlinder)
Fletchlinder VS Lucario (Lucario)
Hawlucha VS Lucario (Hawlucha)
I don't see Korrina wielding Mega Evolution against Ash as it would be extremely unfair. Ash couldn't beat Lucario when it wasn't mega evolved, so I don't see him miraculously beating it when it does evolve.
Ramos:
Fletchinder VS Weepinbell, Fletchinder wins
Fletchinder VS Jumpluff, Fletchinder get's recalled
Hawlucha VS Jumpluff, Hawlucha wins
Fletchinder VS Gogoat, Talonflame wins (Fletchinder evolves)
Again, why is Ash using two Pokemon against's Ramos' three? After we had three mid-gym battle evolutions in BW, I'd prefer to not see those for a while, if ever again. Fletchlinder deserves its own evolution episode dedicated solely to it, not just thrown into a gym battle. What I can see:
Hawlucha VS Weepinbell (Hawlucha, recalled)
Froakie/Frogadier VS Jumpluff (Froakie/Frogadier)
Froakie/Frogadier VS Gogoat (Gogoat)
Hawlucha VS Gogoat (Gogoat)
Fletchlinder VS Gogoat (Fletchlinder)
And then we'd have two different kinds of gym battles: Gogoat gets some praise by taking out two Pokemon and Lucario sharing the spotlight with Machoke VS Korrina. I don't think Froakie will evolve by the time they get to the Coumarine City gym battle, but I have it there just in case.