no, this is incorrect.
Lets compare,
(2.9dpp for ease of math)
(200k dmg per hour, also for ease of math)
(enough armor to take 1.0 hits so healing does not effect the math)
L5 Outcast 420hp 1.45ped per kill 476kills an hour 34x multiplier to global
L20 Warrior 1600hp 5.52ped per kill 125 kills per hour 9x multiplier to global
L57 Clan Warlord 4720hp 16.28ped per kill 42 kills per hour 3x multiplier to global
So if using the same dps vs these 3 different mobs, you will global more on the L20 than either of the other two.
L5 Outcast has low enough hp that it requires a 34x or higher multiplier to global which doesnt happen very often.
L57 Clan Warlord only needs a 3x or higher multiplier to global, but you only get 42 kills in so still can not global often. (of course globals will be much larger, and anyone hunting these will have much higher dps so will still be seen to global alot, but you said same dps which is not the case.
L20 Warriors fall in that happy middle ground, they only need a 9x multiplier to global so any 'mini' is still over 50ped and visable as a global, but low enough hp that you can get a higher kill count and more looting opportunities than you had with the L57s so therefore more global total per hour for the same dps.