Letting people purchase commissions made some degree of sense in the era that it was done in, especially when there are no military academies training professional officers as if they were clerks.
Someone else can cover the Intendancy, but I do want to say that the idea that obviously officers should obviously be selected purely on the basis of academic merit based on institutions that don’t exist…
I suppose in the Infinite Sea there’s Takara’s and Kian’s examples, but in the Northern kingdoms? Purchase is a step up from the alternatives of that cultural context.
When 90% of what is expected of an officer is to be brave, authoritative, and able to bear the expenses of his rank (which may very well including covering part of the cost of the unit in question), the idea that the best officers are (description of Sandoral goes here) is going to take a bit of work to getting going.
I’m not saying I wholly support it - but if I had to choose between “commissions are available for purchase” and “military rank will be based on social rank. Say hello to Lord Lieutenant Colonel Renard d’al Findlay.” (instead of merely Lord Lieutenant Renard d’al Findlay), I’d go for the former so fast it’s scary.