why would it be important that "Crown manufactures" any given % of the truck, and how did you get those numbers?
I am under the impression every other truck is 100% manufactured. is Crown growing 15% of the truck and manufacturing the rest?
are you trying to discount how much casting, machining and other manufacturing is done for Crown by vendors? are you trying to discount how many controllers Crown has used that were not Crown manufactured, or just to point out they grow 15% of their own parts?
what % of part numbers in Crowns parts catalog are manufactured by Crown in New Bremen Ohio?

if I take 3 or 4 trucks, I can find a part in each truck that is not as good as the part in each of the other trucks, but that does not mean the truck is better or better for the amount of money it will cost to purchase or own. (brakes not as good on truck A, as my truck Z, lift not as fast above first stage on truck B as on my truck Z, Carriage not as see through on Truck C as on my truck Z)
never (or rarely) mentioning that the better points of trucks A, B, or C over truck Z.
All designs are sets of compromises,
your mileage may vary