Very common for Roman client states, actually! While by the Late Empire, when it was most common, it was… probably counterproductive, in earlier periods it was actually very effective. Roman ‘subsidies’ to their client states reinforced the power of pro-Roman elites and improved the capabilities of the clients to repel their neighbors - which was usually their primary purpose, as buffer states.
Romans gave subordinate territories tribute? Seems counterproductive.
Very common for Roman client states, actually! While by the Late Empire, when it was most common, it was… probably counterproductive, in earlier periods it was actually very effective. Roman ‘subsidies’ to their client states reinforced the power of pro-Roman elites and improved the capabilities of the clients to repel their neighbors - which was usually their primary purpose, as buffer states.