(Spoilerish) Explaining the abnormally accelerated growth rate

QueenElizabethShaw
MemberChestbursterMay 23, 2017I just replied in another thread, then realized this is actually worth a discussion all it's own.
When we see the scene where David bombs the "engineers", we see what appear to be full grown creatures bursting out of these humanoids almost within seconds.
I have been wondering for some time if this is indicative that when the intended dose of black goo is delivered to the host, it is meant to birth a full grown creature instantly and that accelerated growth rate also means a much shorter lifespan.
It is possible that the variations we are familiar with which takes hours or perhaps a day to gestate, are an incomplete form due to a smaller dosage of the black goo.
These smaller dosage instances may mean that the developing organism is forced to rely more on the host DNA than the black goo and take on more of the host traits such as longer gestation and longer lifespan.
The creatures from the bombing may have died only a few days/weeks after the event.
Furthermore, if the eggs on the derelict had been there for 10 to 2000 years, it is possible that the face huggers aged causing genetic deterioration/loss of potency. This could have led to stunted growth on all accounts. It could even perhaps affect the amount of time it takes for the hugger to implant it's payload.
Thoughts?