I disagree that zero compression, as recorded on a compression test, equals zero power, unless of course there is catastrophic failure to your two offending cylinders. (Broken pistons). If this was the case, you would definitely have other indications of poor engine condition. Your engine wouldn't run properly.
The compression test that your engineers would have carried out, involves attaching pressure gauges to the cylinders by means of an adapter screwed into a spark plug hole and turning the engine over on the starter. At no time is the engine actually started.
Your problems are likely to be caused by worn/burned valve seats and/or worn piston rings/cylinder bore. The wear is allowing the pressure to escape and nothing is being registered on the gauge.
This does not mean that there won't be some compression there when the engine is actually running. The increased speed of engine rotation and therefore linear piston speed will build up the pressure faster than it can escape. The resulting burning and expansion of the fuel/air charge will provide power.