Ok, found where prototypes have limited replacements. So what is the best way to handle prototypes? Buy them, then when damaged with no replacements, disband them and buy something else?

Does this have anything to do with prototypes? If so, that negates the value of prototypes.

In playing I had an armor unit that would not give replacements. I had prestige points and other units replaced correctly including other armor units. In next battle, 3 different armor units would not give replacements. Any thoughts why this happened?