I think you can have 2 launch script as scripts path's are different &
rules are belongs respective script. 1 person can a do 10 task in 2 days
then 2 persons can do the same in one day. We may need to compromise
with Performance & best practices. I would suggest If you have access to
ADobe launch & have dev environment then please give a try from your end
& let us know your findings.
If both Organization have similar website functionality(including
datalayer) and tagging requirements(including analytics & 3rd party
Marketing tag) then they can have a single launch script. If requirement
is different then go with 2 separate launch script.Also if frequency of
tagging request is high & needs to be implemented sooner then can have 2
launch script. This will enable 2 tagging resource to work
simultaneously.This is just a suggestion. Please do some more research.
All the best.