Same Language Different Accent

I've been fortunate to live and work all over the United States, and one thing I've noticed is the little variations in word choice and pronunciation that makes a local accent what it is.  We all speak English, but it's the little things that makes an accent.

For example, I'd never heard of referring to an interstate highway as "The 22" until I spent time in southern California and Nevada - it's a thing of theirs that I haven't heard in other places I've been.  And there is of course, the well-known word choice in the United States of a soft drink being "soda", "pop" or a "Coke" (learn more about that here).

Ackshually, where I was born, it's Coke.

It turns out that there's a similar phenomenon in the martial arts.

Different groups within the same basic art has the same sort of differences as regional dialects.  Much of the language of the art is the same, only with different accents, both verbal and physical.

I often attend seminars in which the instructor is of the Modern Arnis "family", but a different "branch" than the one I've studied or the one I started in (those are two different things).

Much of the content covered I am usually somewhat familiar with, however, it's done slightly differently than the way(s) I've been shown to do it.  Not enough to cause me too much trouble, but enough that I had to think about it a bit.

Sometimes it was a different terminology, sometimes, the rationale behind what we were doing was a little different...

But it was still the same language of Modern Arnis. I understood the words, even if the accent was a little strange.

We all "speak" what Remy Presas taught us, but don't get me started on the different ways people will try to imitate HIS accent. Click on the image to see the source.

I imagine different lineages of other martial arts must be similar - same kata (perhaps performed slightly differently), same sets of techniques (maybe with different names or applications)... but it's still the same martial art.

It's still the same language.

It got me thinking - at what point do these "regional" variations end up becoming a new martial art? Is this how different branches of martial arts split off in the first place?  Gradually, like languages change over time until they don't sound like the parent language at all (see English and German).

What do you think?