Sci heals are maybe a little OP on the ground, but then Sci-ANYTHING is really, really underpowered in space. Currently the only place in PvE (and PvP too, sadly) playing sci has sense is in ground missions. Because of it's heals. And then I doubt you say that heals are OP when sci uses them to help you.
Leave sci alone, they are already almost unplayable and nerfing their ground heals will erase them as a viable choice for anything in this game.