No! I only do 4-5 at time due to physical/stamina issues, and fridge capacity(need to buy a second fridge/freezer this year).
I wish I could do them all(this year is 9 cockerels and 6 hens) at once and only clean up once. But part is also timing, 3 cockerels will be ready in a couple weeks, the others a few weeks later(tho I may do a couple/few early)....old hens go in fall after the pullets are laying and before winter weather clamps down.
I slaughter cockerels at 13-16 weeks, before they start causing chaos and while still tender enough to grill for that crispy skinned deliciousness. Not much meat but the grilled bones make for some excellent stock. Anything older than that I pressure cook until meat is done and is saved aside then a couple more hours to get that bone broth.
Resting the cleaned carcass in fridge for 48-72 hours for rigor to pass is essential for chewable meat from any bird(except maybe CX?). Tho no homegrown bird I've eaten, layer or meat breed, is as soft as a grocery bird, they are more 'toothsome'.