No I mean it's hard for a melee character to keep low level merc alive in hell cows
For my zon it was easy, A couple of hell cows and level from ~1x to 60.
But mercs (especially barb and pole merc...) die easily and that's what I mean by "takes long"~

Mercs get no exp if your party did the kill, suffer exp cut if you do the kill, and if the monsters are higher level (10? range).

For sorc and zon it's very easy to level tho.