You are.not entirely right here.
Yes, tank rifle is good as starting weapon for hunt, but ilvl 239-245 proper ranged weapons (base speed 2.8-3.0) outclass it due to how scaling works. Lots of hunter abilities are tied to his ranged weapon damage and with slow firing weapons end result is far greater. Aimed shot, Steady shot, Multi-shot, Kill shot will be way effective with Rowan's.
It's same concept with Fwarr, where they are using Shadows Edge in main hand till 277+ 3.60 speed weapon. SE just outdamages even 271 weapons from 10HC/25NM LK. Stronger Slam, WW, HS, stronger bleeding damage aswel.