Shattered Paradise is an expansion for Tiberian Sun on OpenRA, its goal is to (im)balance the game by adding new factions (Mutants, C.A.B.A.L. and Scrin) and reworking the original sides, all of this to create a game a little more varied and balanced than TS. The mod puts a lot of emphasis on making the factions as asymmetric as possible.
The worker unit is CABAL's Basic infantry, it's a cyborg equiped with only what is need to perform maintenance functions along with some self defence capabilities, CABAL does use these units on the battlefield, but it's cheaper cost means that they're not as good as proper combat cyborgs. As any cyborg, this unit has nanobots that repair any damage sufferend on battle, and the Workers don't have the necesary augmentations to survive fatal wounds (it won't lose it's legs and keep fighting when killed the first time.).
wow that promotion icon is really cool. where is that from? can't remember that being in vanilla TS. I know of promotions of course but I don't remember the big pop-up icon.
IIRC those show up when you grab a crate containing a promotion, I can't say for sure though, I may be wrong.