i believe it was by design that the summoning dolls are limited to a certain radius around the specific spot they were summoned at. if so, then so be it. i have gotten around this very easily :
1) using them as a mule that eliminates my encumbrance up to the dolls weight limit (unsummoning them back to my inventory, where they weigh 2, regardless of what they carry)
2) in combat, pause, and summon, then select all, click on target, and unpause. wreaks havoc on the enemy and they become infinitely useful.
for some reason, my summoning doll had 4 skill points to spend. i don't know if this was due to some level upgrades the deathknight did, or if this is normal. but when i used 3 of the points to boost its own summoning doll upgrade skill, i noticed that no more skill points were made available.
is it possible for the summoning doll to only receive skill points if the upgrade is assigned by a character other than itself?