Have you made your own cfgloottables i assume by using the loot compiler?
If not i suggest you do that, In there you will find a file named LootItemGroups.h which containes all the items and a number infront of them, That number infront if the "weight" chance of an item spawning in each group when its called by a "building". The higher you go the more chances the lower you go the less.
A quick example:
having all set to 20 means (obviously im gone above 100% chance for that pick but doesnt matter really unless you care for "precission"). So what it really means is that it will equally pick from all of the above to spawn them when called to spawn an SMGAttachments.
50, optic_Holosight_smg //50%
5, optic_Holosight_smg_blk_F 5%
10, optic_ACO_grn_smg //10%
5, optic_Aco_smg //5%
5, optic_ACO_grn //5%
25, optic_Aco //25%
If it were to spawn this example it would have 50% to spawn optic_Holosight_smg in the SMGAttachments of a loot position ingame.
Explanation on what you've done, Now that you took out the zipties and other trash it will look into what you have defined in the building loot for military gear to spawn previously it was Zipties (etc), Uniforms mil, Backpacks mil, Headgear mil and so on. Now because you removed the zipties etc it has less items to pick in small slots, So its picking what is left (flares, grenades). If you do not want only grenades in there then add in your loot table in the grenades section some more small items that you think are useful, Maybe some mags. In the end its up to you but given the above i've typed you should at least understand how loots work.
This is what my military buildings loottable looks like, This is where you reduce the amount of Explosives etc spawn from the loottables.h in the loot table compiler.
Hope it helps.