Search Results: way to a guy's heart

This is a long story but;
My best friend is a serial dater, which I'm not mad about. As long as he's being safe I support him.
That said after 1 week of dating someone new they always want to meet me because as my friend says "I talk about you a lot so they want to get to know you." To which I say, thats nice but it's been a week, shouldn't they get to know YOU first?
Regardless I try to be a good friend and meet them anyway because I know he wants my opinion.
The real problem comes in when my friend inevitably gets bored or finds some fault with this man no longer than 2-3 months into dating him.
At that point since we did the whole try to get along because your dating my friend thing, almost every time he breaks up with someone, I get harassed by the hearts he's breaking.
I no longer accept friend requests on any platform from the guys he's dating but despite that they still try to message me asking about my friends feelings.
I will readily admit only about 50% of the time do I believe my friend has a legit reason for ending the relationship, so it does make him an asshole and I get them wanting answers more than "it's just not working out"
My question is am I a bad friend for asking that he dates them at least a month before involving me? Is there a better time frame? Or is this a hopeless cause regardless of timing because my friend is great in so many ways but dating isn't one of them?