While it looks like at first glance, the problem is that none of those have an 11% boost and the other problem is that a lot (For me it's all) of the stats don't play into the actual game. You should be looking for items that will work for you all/most of the time. Paratroopers, attack helis, mortar troops, guerrillas, and a few more are all units that people rarely ever use. I think when you're lower level you use them because you haven't realized how useless they are. So to use precious supplies to unlock those levels is not a good idea. You can get items with multiple 11% tiers but if they aren't things that are useful than you should sell. For weapons its the same and you shouldn't switch your game play. Like getting mortar troop dmg increase stats and than you waste resources to upgrade those troops.
For armor, the best things (Just my opinion) are those that affect planes because almost everyone attacks with planes and once in a blue moon you get those using bombers and paratroopers, defender dmg/hp/spawn time, ranged siege and ranged troops because in all likelihood they get used. Raiders perhaps as well depending on the frequency of attacks.