[@Dynamo Frokane] Age has been added, 25 is correct.

[@Lmpkio] It's quite possible that they knew of each other. The Balthazars were/are a somewhat high profile group in the Northern Frontier (with the exception of Hawthorne, who's mostly managed to get away from the spotlight). 

If you intended for Alexandar to be an enlisted man, the rank of Sergeant First Class might be suitable, giving the number of years he's served and his capabilities (That's the next step from Staff Sergeant).

If you intended for him to be an officer, a Major or Lieutenant Colonel would be more likely, I'd wager. It takes about 20+ years of service to become a Colonel, typically.

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Either way, it's entirely possible that Hawthorne and his mother fought alongside or served under Alexandar, and he may have been the one to promote Hawthorne to Sergeant and Staff Sergeant, depending on if you choose to be an officer or not (This is war my military knowledge gets a bit fuzzy, but I'd say it's plausible). How Alexandar feels about the man Hawthorne is and was however, is all up to you.