Is it actually an improvement for Splinter to start out as Hamato Yoshi?

[neatoman]

My argument here isn't going to be about how little sense it makes for Yoshi to mutate in the same incident as the turtles. We can pretty much point to how the "closest living thing" rule makes no sense in Fred Wolf, Archie, Nick, Rise or any other iteration that may use it (either Yoshi becomes a turtle or the turtles becomes rats in that scenario). I won't focus on how the timeline of events in FW makes no sense, how Nick Splinter seems to forget valuable information by the time the series actually takes place or how Rise Splinter just doesn't do anything with what he logically knows. All of those are just the result of careless writing and IDW is the only one that handled the concept of Yoshi and Splinter being the same well, and even then they're not strictly the same person there but rather different incarnations of the same soul.

No, instead I'll focus on the big thing people seem to consider an improvement, his martial arts skills.

Now, on the surface it certainly looks like an improvement. In the real world there is no way for a rat remember complex human moves, nor can they really emulate them. So indeed, a human trained to use them would certainly know them better. It would indeed seem like Splinter the rat would never be able to teach anyone the moves, while Yoshi the human would. But there is a factor here that is overlooked, the timespan. See, what prevents Splinter from refining his abilities once he's mutated?

As stupid as the "learned it all from a textbook" explaination from the PD movies is, it did make me realise something important, who ever said his time learning martial arts stopped with observing Yoshi? He had fifteen years between mutating and sending out the Turtles to avenge Yoshi, that's plenty of time to figure how to fight properly.

Maybe you're thinking something along the lines of "Wouldn't him spending time training take away time spent on training the Turtles?" right now. The answer is not really. While it might be easy to simplify a teacher/student relationship as "teacher knows, passes it on" but that's not really accurate. It's more like "Teacher knows more than student, student finds flaw in teaching, teacher corrects their error, repeat". Anyone who asked plenty of questions in school should be aware of this concept, sooner or later a gap in the teacher's knowledge will be revealed, thus the teacher will learn to improve. Given changes to the curriculum, teachers are constantly learning new information themselves so they can be better teachers, part of how this happens is input from students. So it is certainyl conceivable that he can easily learn alongside his students.

So pretty much the only reason to make him start out as human because "it would make more knowledgeable" would be to make sure he taught his students quickly. But if he has the better part of two decades on his hands, constructive students, access to the Battle Nexus (i.e others to help), and yes, even a textbook, then it really shouldn't be necessary.