Yes, your boys will start fighting as they mature and even if they dont, your girls will soon have not feathers on their backs! One rooster can do that with 8 hens, let alone 8 roosters!!
Heated coop?! Very nice!! Spoiled babies!!
Another plus, if you find new homes for most of the roosters, you can get more hens!! You coop won't be big enough for too many more birds in there. OR, you could build a couple more coops and separate the birds out by breeds and get lots more hens?!!!!
Heated coop?! Very nice!! Spoiled babies!!

