Pet shops get most if not all of their turtles from the same group of breeding pairs(most of which are inbred), so it's highly likely that most turtles you get from say petco or petsmart(higher for profit companies) come from the same group of mothers. Obviously they are spread out throughout the entire country and I don't expect them to be brothers in blood. Obviously this is going too far with the science mumbo jumbo and I don't expect a comic or cartoon to follow it at all.
My main point is, they lost their iconic mouth shape , the bodies can do whatever the hell they want as Ralph and Leo should look larger than Mikey and Don. I also strongly encourage color changes as turtles are never the same shade of green. I don't even care how tall or short they are as long as they have the same turtle looking mouth.
But that's just me being picky., I just hate the designs, not the idea of adapting the series to make a new version. If they did have designs of them in this style they went with that looked good, I've love to see it.