I would say yes, a woman can be too slutty for me, even in the lifestyle.
At first I was intimidated by my future wife having a number that was four to five times mine when we started having sex after we met, even though when single she had a rule of like five dates (she would almost always pay) and two months before having any sex with a guy. Some boob play and blowjobs as they got close to those hurdles and if all was going well. Then I embraced her past and enthusiastic attitude towards sex, so much that after we were married I encouraged her to hotwife. But it was still a slow, measured thing with guys she either knew from her past and got reintroduced, or men she knew and slowly started down the path toward seduction with me involved along the way to make clear what was going on.
Now that we play only within our closed group, I like it a lot better. It's far away from stranger sex, we all know each other well, and even care about one another. My wife still plays, a lot, but it is limited to six other well-chosen guys (and their wives), which seems to me a lot better than fucking random men. There are never condoms, which gives me comfort that because we are closed the danger and nastiness of stranger sex isn't there.
There is in our group, however, plenty of kinky, crazy, "slutty" play, dirty talk, name calling (you haven't lived until a guy and your wife use the word "cunt" while fucking), or watch two other guys DPing your wife. But somehow it is nowhere near slutty to me as if she just had quick, normal sex using a condom with a stranger.