Hell, still in Italy but centuries later, Machiavelli HATED using mercenaries as city guards as they weren't loyal and could be bought by the enemy or if they were losing, could abandon posts or switch sides.

He ensured the city guard were made up of local men as they were defending their HOME so new if they failed, their families might be in danger. He even wrote a book about this and how to rule, pity the only one these leaders read is 1984 as a guide..