I think that what may be the issue is that there are shifts in the type of hair being used as well. Or rather, I sound like I know what I'm talking about, and I don't, but what I mean is that Clover and Baby Stargaze comment, that's very much the case. A lot of the ponies in these later years have a slightly different quality to their hair. It's like the tinsel is different in the hair for the Jewel babies than it is from earlier ponies, and the family friends and family babies have entirely different hair with the horizantal stripes.
I haven't compared Hopscotch and Fireball though that may or may not relate to batch.
Moondancer is pretty close to Snoepjes. I haven't done an exact comparison, though, because my Snoepjes is MOC.
Bon Bon is a later G1 from European line so I think it is possible she doesn't have an earlier pony exact match. Love Petal maybe? I can't think off the top of my head of any other G1 pony from 1993-4 that has BonBon's hair colour.
Oh, possibly Princess Sparkle...? That might be the same...?