Why does the Type 60 SPRG only carry 10 missiles and not 12?

in the game, the Type 60 has 8 rockets in the hull and two loaded in the guns. The data about the vehicle shows that it is historic, i.e. it carries 10 rockets, and this is where the question arises. Since 2 missiles were already loaded, each commander loaded additional missiles in place of these two. Doesn’t this seem weird and a little stupid? please give me reasonable answers.

It is the same as all other tanks. You can carry what your racks can carry. The game just starts you off assuming that your crew has decided to load a round prior to spawning in.