[Scrubosaur]

It's sounds like the mechanic is a little too complicated. Velious dragons dispel would always dispel a set number of slots from top down regardless of what was on them. Casters NPC's would dispel your top buff slot every time they cast a higher level dispel. If it was a low level NPC casting dispel it would either be resisted or not strong enough to remove the buff. More than likely dispel mechanic removed buffs from the top buff down (hidden counters) but there was no over lap to the second buff unless it was a very high level dispel then it could remove more. PC vs NPC dispel mechanics might have been different as I remember it taking a lot of casts to remove NPC buffs but the dispel order was the same (removing first spell cast first).

If someone was testing dispel mechanics on live then it does look like there is a mechanic in which buffs after the first one could be dispelled first. The issue with that is if you either click the junk buff while dispel is being cast or less than 6 secs before being cast then EQ doesn't recognize the buff being up and will dispel the first buff that had been on longer than 6 secs.