Inconsistencies with Mutants?

[CylonsKlingonsDaleksOhMy]

The Turtles and Splinter are skilled fighters because they are the reincarnated Hamato Clan, but how is it that mutants like Koya and Alopex are so skilled at fighting when they don't have the previous life experience to fall back on?

How do Herman the Hermit Crab and Mondo Gecko develop such radical personalities within what I'm assuming is no more than the span of a single week? Old Hob at least had the "benefit" of being Stockman's lab rat, so he could easily develop skills for weaponry, deceit, and manipulation... but where did Slash become so proficient at meditation and disabling security systems? From one little injection?

This seems to be one of those things where if you think about it critically, it falls apart. You just grin and accept it, so that you can enjoy the awesomeness. But this really bugs me when I allow myself to think about it...