Brigadier, being a yakuza rank, is almost surely based on the (again) military brigadier rank that precedes it (which reflects the number of troops at his command). So it still doesn't get any extra ninja status from that. And yeah, I know Kero is pretty much the sound a frog makes in Japanese. I was basing my deductions on its English name, moves and descriptions of it leaping high and attacking, like with bounce (jump up high or onto things and then basically dive bombing onto its foe). I'd say the English name Froakie comes from Foam and Croak. So both names come from the sound a frog makes, but the other combined words have different influences.
I knew Braixen was a mixture of some word plus vixen, female fox. I wouldn't know the, I guess, French word the first half of the name comes from. *starts looking at the names with more than a passing glance* Fokko, for fennekin, seems obviously Fox (fok) with ko at the end which denotes a child/puppy/kitten/cub/etc. Otoko no ko (boy), onna no ko (girl). Maybe fok has something to do with kindle in japanese, but the Fennekin, would be based on the desert dwelling fennec fox, which boasts the similar narrow face, petite body shape/size, and oversized ears. And kin of course is kin, so it's like Fox-kin or fox-relative/family.
I think chespin's final evolution will turn out tanky and actually look pretty decent, despite its second evo, but he was never a serious option for me as a starter anyways.
I think fennekin's final evo with grow taller, and more upright, flesh out a bit more, and gain a staff and probably look like a foxy version of Anubis. But without the collar and crown things.