execute store result score random itemcount run random value 1..6
execute if score random itemcount matches 1 run data merge entity @s {CustomName:{"text":"Calvin"}}
execute if score random itemcount matches 2 run data merge entity @s {CustomName:{"text":"Edmund"}}
execute if score random itemcount matches 3 run data merge entity @s {CustomName:{"text":"Frank"}}
execute if score random itemcount matches 4 run data merge entity @s {CustomName:{"text":"Isaac"}}
execute if score random itemcount matches 5 run data merge entity @s {CustomName:{"text":"Milton"}}
execute if score random itemcount matches 6 run data merge entity @s {CustomName:{"text":"Henry"}}
data remove entity @s[tag=zombmerc] Tags
data merge entity @s {Tags:[hmmerchant,plussed]}