Eye Layers(?)

[manic blade]

Hello, I am pretty new to rigging or this in general, so I would just like to ask, is the iris and pupil better to be separated? sorry if it sounds dumb but I genuinely don't know how I should go about this, any advice would be great, but if there is a "general" way/tutorial to separate each layers, I would appreciate the help!

[prisma relic]

if youre planning to have them move separately you separate them

if youre gonna just put them in a deformer together and never move them separately, there's no reason to separate them