The question is "Performance of what"?
Let's transpose the question onto real life:
Can there be such a thing as too many children? For example, if I had a friend with 10000 children, would that affect overall performance compared to 10 friends with 1000 children each?
"Clearly" the tradeoff is that the more children you have, the less time you have for each of them, and, if you die, more of them will be orphaned.