Adding satellites to my CBR40

I have an Orbi CBR40 router with a RBS20 satellite and want to add one more satellite to extend my coverage to include a small guest house about 30 ft away.    I would prefer to simply add an Orbi satellite to the guest house which would be "downstream"  of my existing RBS20 without rearranging the location of the router.  Each node is about 30ft apart.  

Does my route have to be in between the satellites?  Is there better satellite solution than the RBS20?  It ouwld be a hassle to have to move the router.