I have very bad luck with Dragon-types. I have already lost Tyrunt, Gabite (is it supposed to be this shitty?) and Axew.

I'm after the 4th gym, my team is:

Meowstic
Talonflame
Greninja
Flaafy (in the process of training)
Diggersby HM slave

Who should I add as the 6th member?

I have:

Golett (with Klutz unfortunately)
Snorlax
Combee
Gulpin
Rhyhorn
Hippopotas
Slowpoke
Mr. Mime
Stunky
Drifloon