This is one of those situations where there's a real distinction between 'can' and 'should' You absolutely can use 7 texture sets on the turret and there's no reason to not use 7 texture sets on the turret if your use case justifies it i.e its big and important and you're taking full advantage of the resources you're using…
You may have to elaborate this to get a more suited answer. Because six textures with six different UV maps (UDIM or not) with the same resolution.. of course will give you a higher pixel density.. or using one six times bigger image in the first place (?).