I raised five different Brahma cockerels last spring and I will say that his comb size and lack of significant sex feathers seems pretty normal for a cockerel at this age. Now some of mine grew a bit more on pace for most breeds, I had these two that just took their time. My buff one pictured had almost no saddle feathers at 16 weeks and had an almost bare back, despite definitely not being picked on and being fed gamebird food with 30% protein. When you have these big birds, their frame develops faster than their sex characteristics. Here are the two I mentioned at 16 weeks and a picture of one now (8 months old and 11 pounds), showing how it all just takes time to look like full-on roosters 
he seems very docile and mellow at mo and Ice read the breed can be like that so will be nice if he stays that way
