Yeah, I would. I've known a couple of guys who slept around A LOT, i.e. in 3 figures. Both spent a while working in jobs that gave them easy access to young women - holiday camps, etc. If you are good at flirting with girls, getting laid isn't really that difficult.
However, it doesn't mean he knows anything about sex, because you learn most from a steady relationship. You can have had 200 sex partners and still be absolutely ****e in bed.