What benefit is in building Spartan type government when playing as Hellenic faction?

The standart Hellenic-type (second government building) takes less time to build, is cheaper and has overall more benefits (Spartan government building reduces trade and probably lowers time and money for military type buildings). I peek into buildings textfile and found that every hellenic unit can be trained with Hellenic type building and Spartan does not allow to construct some buildings...

So why bother with it ?

I expected some elite unit or some building for greater experience for recruits.