I didn't play too well in this match, but I wanted to upload this one anyways. I didn't see the combat engineer put in that much work to be honest.
I saw the Repairs go off, but I didn't see the engineers use purge too effectively. The spell should debuff nightelf's rejuvenation spell or Orc shaman's bloodlust. I have looked into the match a lot closer in the replay and did not notice any of those spells get purged. I mainly just saw them purge randomly on any unit. You guys can try out the combat engineers, but I believe that there are many better bonuses for Dwarf.