It seems to me that the first-strike advantage of the extra range is countered by the passive first-strike absorb ability of grounding totem
And yet to get the advantage of the grounding totem you have to stay within its range, making you somewhat stationary. But ya you can close 5 yards really fast. But as the shaman you just can't stand there and wait for the mages to come into your range you HAVE to be moving towards them, which means that untill you hit FS 35 yards range (after patch) you cant cast, or the LavaB with the insta cast mod. Plus in the case of boxer vs. boxer yur lead will be in range and your followers won't ....

I dont know looks to me like the group moving is going to be at the disadvantage and the mages dont HAVE to move. I think the shaman lead goes down first then the mage lead goes down to LavaB then ....