I should have delayed and combined this all into one message.
The Order of the Bath does have numerical limits but Her Majesty is permitted to exceed them in special cases (and they are fairly high - 120 GCB, 355 KCB/DCB, 1925 CB).
And the Order of St Michael and St George does have limits - but they are fairly high - 125 GCMG, 375 KCMG/DCMG, 1750 CMGs.
I stand corrected. It's been a while since I read up on British orders of chivalry.