I would like to know what you consider to be small & large. Without that, I feel that we can't really help
After a few (cough) decades in real-time embedded development the biggest s/w development team I ever worked in was about 11, IIRC.
Generally, it tends to be 7 or 8.
Coincidentally, we got a new s/w manager recently & yesterday he announced a reorg saying that in future all s/w teams will have 4 to 7 members.
I think that when it gets above 10, it gets to be unwieldy and naturally breaks down into sub-teams anyway.
Are you talking about small projects, rather than teams?
There are 8 of us on s/w development at the moment, but I have daily interactions with systems engineering, the project & the s/w architects, the firmware/hardware guys and the verification team.
We are probably between 40 & 60 in total on the project - could that be what you are talking about? I am afraid that, much as I would like to help you, your question is not very clear.
(posted as answer, rather than comment, due to length. I will update to a true answer if the OP clarifies)