The frizzle has a straight comb, and the other is some kind of flat combThe one to the left seems to have a very flat comb.. id be leaning towards female until there are signs showing otherwise. I've had several slow feathering females, and fast feathering males (aka Heartbreakers!!)

Iām pretty sure the frizzle is a Roo, heās chest bumping and pouncing /mock flogging at every chance he gets.
Once theyāre old enough, Iām going to dump them in the run and have the hens instill some manners into these two!