Sages have an AoE that leaves a HoT effect in its area for quite a while. They can cast that and it will keep healing while they are on the move.
They have Force Armor to buy them time.
They have Healing Trance which is instant and applies a HoT.
They aren't exactly stationary.
Every class in this game is a "plant and cast" healer. The healing mechanics are not particularly diverse or complicated. Much as I prefer this game over WoW (or I could easily play it instead...), SWTOR doesn't even come close to WoW in terms of healer mechanics, which is remarkable considering that WoW was hardly an obscure title while SWTOR was in development. Case in point, there is no healer in SWTOR that can heal effectively while fully mobile like a WoW druid. There is no healer that can consume HoTs to increase the power of a nuke heal. There is no healer that heals through damage dealt. There is no smart healing. There are no healing wells or orbs a healer can pre-place and a player can pick up or walk over to get their own healing. There are no chain heals. There are no life funnels. There is no ability to let a "plant and cast" healer cast on the move for a short duration.
The mechanics are all "plant and cast." Every class could be called to a greater or lesser degree a "healing turret." Even Scoundrels, the most mobile healer in the game, cannot heal effectively using only instant abilities.
So, whether you like it or not, and regardless of whether or not it also applies to other classes, Commandos are absolutely a turret healer.
Then call them all turret healers and be done with it. When you're comparing classes, and you call one a turret healer but not the other two, it implies that class is the least mobile.