A bit confused as to what you mean, but this may help. When you set a variable like {Variable2} you can only set it to 1 thing.
You can, however, add the words to a list variable like this {Variable2::*}.
So then {Variable2::*} is the list containing Name1, name2 and name3.
To broadcast a count of the number of contents in that list you'd need to set a separate variable that represents the current number on the list. It'd look potentially like this:
code_language.skript:
command /add <text>:
trigger:
#This adds your name to the list
add arg 2 to {Variable2::*}
#Here if the list count hasnt been set it will start at 0
if {name_count} is not set:
set {name_count} to 0
#once a note is added it adds 1 to the total note amount.
set {name_count} to {name_count} + 1
You'd do the same when you remove a name only you'd take away from the total list count instead like this:
code_language.skript:
set {name_count} to {name_count} - 1
Then when you want to broadcast the total amount the list contains you only need to do something like:
code_language.skript:
broadcast "%{name.count}%"