3 Concerning Naugrim, Ents and Eagles

[Findegil]

700 years is for Dwarves not so much. Let assume the Fathers started at once to beget children, since each generation takes 100 sun years get children of their own, generation no 8 would be just born when the Elves entered Beleriand. If we calculate that 3 generations are alive at the same time and each generation would 1.5 times greater as the one before (which is a very high rate considering what we are told about the dwarves):
Generation 6 (the grandparants): 4 x 1.5 x 1.5 x 1.5 x 1.5 x 1.5 = 30.375
Generation 7 (the parants): 4 x 1.5 x 1.5 x 1.5 x 1.5 x 1.5 x 1.5 = 45.5625
Generation 8 (the children): 4 x 1.5 x 1.5 x 1.5 x 1.5 x 1.5 x1.5 = 68.34375
And this is calculated for both Nogrod and Belegost together. How could they already push out a portion of this? And how could these develop to a smaller varity?

If at all this would function with the 144 S.Y = 1 V.Y. calculation, where generation 106 is just born when the Elves enter Beleriand.

Respectfully
Findegil