Can these two be used in conjuction with one another? (Can you pay 4 less for an attachment, attach it, and draw a card?)
Three Man Alliance Plain + Secluded Outpost
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Can these two be used in conjuction with one another? (Can you pay 4 less for an attachment, attach it, and draw a card?)
No.
You're using two separate effects to attach the attachment. Each instance of attaching is resolved completely before the next begins.