What are your comparisons based on? You shouldn't compare 170mp combat engineers to 300mp OKW sturmpios (I'm not a fan of sturmpios but still the comparison is crazy). USF rear echelons never fight against them (but it is probably true that the 5th man is too much, still even if they fought each other I feel that combat engineers would win). Stun grenade is on sturmpios but it is doctrine tied so why are you writing about it? Why do you expect amazing dps from an engineer unit? They have many more useful abilities: they construct buildings, lay mines, sweep from mines, lay barbed wire, can be upgraded with flamer (and here is where their dps shine), they lay demo charges, and probably most importantly, they repair vehicles. On top of that, if you put them behind cover, or in a building, they will stop grens from advancing or even volks - so mainline infantry units. Once they get a flamer and are supported by merging conscripts they can be pretty much unstoppable. You can also put they into a halftrack and clear buildings. Once again, they are too cheap and add up to the result of the Soviets being the dominant faction at the moment.
I dont expect amazing dps on ce's. I dont want them to be 5 men squads. If the demo becomes ussable again i feel their price could use some tweaking towards 200mp. But in terms of combat, versatility or utility or even signature abilities they get the very very short end of the stick. They excel nowhere other then in their price.
I compare sturms because they are engineers just like ce's but are far better combatants Their stun nade is vet 1 btw. They justly cost 300mp.
Pio,s extra sight allows them to support their team weapons and inf without exposing them selfs. You can see without beeing seen.
Royal engies and rear echelons can get ai or at power and get extra hp as the game drags on. All nice added usses wich ce's lack. Hence tgeir just 170 mp price tag.
That you can put them in a halftrack or scout car is irrelevant. Its not like m3 or m5 are t0 or are free. Axis have either t0 atgun or with grens techless snare. Both mg,s of axis can rip through them. Merge keeps them on the field but at a minumum of 20 mp per merge. They are a 4 men squad facing faction wich fight 5 or 6 men squads mostly and have the dps accordingly.