There was some general/writer back in the day who pointed out that doubling a unit's fire power does not make the unit 2x as good as the unit resiliance was not affected.

This is applicable to the mathhammer of 40k where an upgrade that makes a unit 50% more effective in attack does not justify a 50% increase in cost .

10 guardsmen with 2 CC weapons
20 guardsmen with 1 CC weapon.
in CC, no charge.

Both squads put out 20 attacks, averaging 5 dead for both sides. The smaller squad has been reduced to half, 5 models pumping out 10 attacks next turn while the larger squad stands at 15 pumping out 15 attacks next round.
next round the smaller squad is reduced to ~1 guy while the larger squad reduced to ~12 guys.

Of course, such conflicts rarely occur. Usually an attacker geared for offense is kept low so his lack of defensive boost isnt a liability (fire magnet).

Anways, Im looking for the name of that tactical theoretician as I dont remember it.