new and old cov. species!

i dont mind there being changes to the look of the covenant. each game changes a few things astetically. sleeker armor better teeth, new animations.
but not entirely new character design, i believe in halo 4 the elites, grunts and jackals must be a different species or sub species.
and what i hope and from what i see in the halo 2 eh halo 5 terminals the arbiters elites looked normal. so maybe the old covenent races and storm races can both be in halo 5.

ill use the elites for an example.
before halo;ce vs halo 2

-in halo 2 the helmet showed more of their mouth
-their armor wasn’t as metalic
-their thighs and feet are more covered
-their jaws and hands are more reolistic
-and their color sceme included purples and teal instead of all blue
BUT over all they were nearly the samegraphically updated

halo 2 - halo 3
the armor changed to be more intricate but the elite just got beefy

reach changed their body a little
updated/ life like mouths
mid leg joint more flexable/defined *above foot / under knee cap

jackals used to look bird like but now more like reptiles

they are sub species, they have explained this already. in halo escalation you can see the old jackals http://img1.wikia.nocookie.net/__cb20131212005330/halo/images/1/11/Arbiter_fighting_off_the_Covenant_Remnant.png if you want read the halo wiki it will explain it all c: