The idea was to
only use them for their main function in research/production/medbay and as a last resort in base-defense.
The main difference (combat-wise) between them and soldiers are the lower avarage stats (they still need to be playtested later on).
Give them your spare weapons in base-defense and use them as you do with your soldiers, but do not assume that they will survive long or hit anything. For this very reason they are not intended to go on regular missions.
Also they will get their own skins (scientist-models already exist, but ones for workers&medics are still needed) and ranks (one symbol per type) ... but this is rather low priority right now since you can only see them in the hire-screen. See that (EDIT: the existance of visible medics/workers/scientists) as a gimmick for now.
Before the discussion starts about using them in battlescape ... it sounds nice at first, but then i would rather use a specialised soldier (what stat to use for here? maybe mind, maybe a new one -> discussion needed) for medic stuff then a surgeon in a white gown
Think of them as the ones that don't want to get theirs hands full of blood ... enemy blood that is
Werner