Trying to understand modifier factors...

[Tilarium]

Playing my first game with the First Contacts DLC using a Payback origin. I drew the Wanderlust event, I'd have rather have had either Mass Extinction or Radical Cultists. So I started looking into it and saw that both the Broken Shackles and Payback origins have modifier factor's of 0 while Wanderlust has no modifiers. Does the factor = 0 mean that it's impossible for those events to be drawn? I would assume yes because Void Dwellers and Shattered Ring both also have a factor = 0 for the Mass Extinction event. Here's the cut and paste from the events file:

# Starting Event gatekeeper
country_event = {
id = country.900
hide_window = yes

is_triggered_only = yes

immediate = {
random_list = {
# Sublight Probes
10 = {
modifier = {
factor = 0
OR = {
has_origin = origin_broken_shackles
has_origin = origin_payback
}
}
country_event = { id = country.258 days = 360 random = 10 }
}
# Radical Cult
10 = {
modifier = {
factor = 0
OR = {
has_origin = origin_broken_shackles
has_origin = origin_payback
is_eager_explorer_empire = yes
}
}
country_event = { id = country.200 days = 30 random = 10 }
}
# Wanderlust
1 = { country_event = { id = country.1000 days = 30 random = 10 } }
# Mass Extinction
10 = {
modifier = {
factor = 0
OR = {
has_origin = origin_broken_shackles
has_origin = origin_payback
has_origin = origin_void_dwellers
has_origin = origin_shattered_ring
}
}
country_event = { id = country.1100 days = 30 random = 10 }
}
# No starting event
69 = { set_country_flag = starting_event }