Well those aren't the only breeds they have LOL! They definitely have an Easter Egger or two in there. None of these breeds have pea combs or beards. I would guess Ren is Australorp x Production Red
A Welsummer crossed with a Black Sexlink would have yellow skin so Ren is very likely not that cross. Stimpy is definitely not a Production Red. She is bearded with a pea comb, likely indicating some Easter Egger genetics. :)