For sme Cta People 1 is too many, for some 7 0r 8 is fine.
You sound like a Good Guardian who knows what the costs of taking in New Faces would be, There are 12 Found Cats, and when the Vet came there were 3 who got away, that I simply cannot catch.
I had John in a carrier but he went ballistic and I had to let him out before he hurt himself.
He and Rocca have not had shots in two years.
Right now 12 is the limit due to age budget and infirmity.
We hope that you can help as many as possible without taking in too many.