I remember sometime ago (after Interlude came out, but can't be sure exactly) that when an OL did his HoP and I did my CoL, they both stacked and remained on the buff bar. Now, I see that HoP (which is higher level than my CoL) "deletes" my CoL and remains alone. Has something changed? Was this due to level difference or too many buffs? Can someone else verify if they still stack?
It is so... the only thing that seems to "stack" not "overwrite" is Hop/CoL + Greater (group) heal.
I've been in parties with SE many times and those two were always pumping HP together.
But when I got off with my HoP and our WC cast CoL - HoP always gets overwriten by Chant of Life (higer skill lvl of CoL in comparison to my HoP - WC is 72 I'm 68).
No overbuff. But it seems that we get both initial "boosts" from the two - but later on only the chant/HoP that has higher skill lvl remains and "pumps" HP back.