I would recommend.
option1) Join ARS02 to existing ARS01 with same shared SQL\ARS01 db. run install ARS (same version) on new Server and point to existing SQL\ARS01 db.
option2) Join ARS02 to existing ARS01 with SQL replication SQL02\ARS02 db /Subscriber to SQL01\ARS01 db /Publisher.
option3) Independent ARS02 (independent of ARS01). Install ARS02 with SQL\ARS02 db with option Export data from existing ARS db (Source SQL\ARS01 db to Target SQL\ARS02 db)
I am also having question for this from customer. Are the options and steps still applicable for v7.2? Is documentation available already for this? thank you.