Earthborn Slingshot

Thinking today and browsing the PP forums I found and am thinking about the following for my Grim list:
Earthborn Dire Troll - 5" speed base, Elemental Communion (+2" SPD when activation begins within 1" of rough terrain)
Grim Angus - Bait The Line (+2" when charging damaged model)
Troll Axer - Rush (5" Charge distance)

Basically if I start my turn, have my Impaler give Grim Far Reach (effective 17" Headhunter range). Impaler finishes activation, activate Axer, who uses Rush animus on Earthborn Dire Troll, end activation, Grim activates shoots Headhunter @ target model, finishes activation. Earthborn activates within 1" of rough terrain, charges model Grim tagged, now with a 14.5" charge reach.

5"(base) + 5"(Charge/Rush) + 2"(Bait The Line) + 2"(Elemental Communion) + 0.5"(melee range) = 14.5" Effective Threat Range

If the following turn order occurs:
Top Turn 1) Enemy runs forward (48"table - 20" for deployment=28" battlefield length, 10" run = 18" left)
Bottom Turn 1) Trolls advance at full speed or slower (18"-5" advance = 13" left)
Top Turn 2) Enemy runs, walks, or stands still (13" or less)
Bottom Turn 2) Trolls can slingshot Earthborn Dire Troll 14 inches, boost hits and damage with 5 fury stat, hopefully caster kill.