Mobs summoned with nbt tags aren't given random items by default as is without.

if you execute the commands:
summon skeleton {}+ {}{} {}{+} {Tags:["mob_setup"], Team:mobs{color:#009c8f}}
summon skeleton {}+ {}{} {}{+} {}
 
Result: the skeleton's bow isn't given to him (actually none of the mobs i tried have items)
 
Expected Result: the mobs should be given their armor and weapons randomly like when you do a normal summon :
summon pillager^ He gets a crossbow