Why do you have to get castle defense in order to build attack weapons? (batterings rams and cats)

Presumably, you have to know a little about what you're knocking down
That is, to make an effective weapon, you have to know the weakness of the thing you're attacking, and exploit it

...I really shouldn't have to make these lame excuses for Req...but then, he has more of a life than I, so I get to answer

You don't get it!

Are you telling me that in medieval times the only army that could own a seige machine was one that had a castle with takeover protection and castle defense?

So all those peasants who had a blacksmith and some type of training abilities, were by some unknown supernatural force, unable build a seige machine.

And who was the police force that would tell them that they could not build them until they dug rocks out of the ground, placed them in a cool wall formation and then placed troops around the rocks to protect the rocks?

Did a medieval kingdom have to learn to tax from scratch too...?
Heck no!
Give Req a little 'artistic licence' here

Are you telling me that barracks mysteriously trained troops out of nowhere, and then made them out of gold, wood, metal and stone?
It's implied...

Every game, you are essentially covering a culture's entire development of siege warfare. All over again

I'm not putting down Req or the game. No defence needed.

I'm looking for a couple of rational reasons why someone building an empire would want to build up his castle protection and castle defense before he considered building a seige machine to attack a neighbor.

Something on the line of "We must protect our women and livestock while all our fighting men are away."

Besides, if I have a barricks, gold mine, woodmill, metal and stone, why do I want to upgrade my castle protection before I build a weapon to attack my neighbor?

You know maybe this question is in the wrong thread.
If this is a -- geeze Req, why would you do that -- thread then it is in the wrong place.