Engineers

[JDR Dragoon]

Also I had Es building a bridge and set them to clear rubble as well, doing both at the same time. You can also build a bridge and patrol I think

Yup, and entrench and build a bridge (at least during subsequent turns, since the ENG will use its full movement to begin erecting the bridge). I don´t see anything inherently wrong with this game-play wise, unless we are talking about a company sized formation. A battalion of engineers is so big, that it can easily accomplish multiple tasks. Indeed, the soviet army ENG BTN consists of specialist units, each equipped for a certain task, but all rolled into one counter.