Amps you can paste new session clips into arrangement right away or you can just play it “over top” of the arrangement session. do you know how to loop a section in arrangement view? what i do is loop the arrangement section, audition the session view clip on top, then copy and paste into arrangement.
after you play the session clip (see apyssjw’s advice above), you’ll have a red box with an arrow in the top right corner of the arrangement grid. when that’s lit up, it’s telling you that session view clips are playing along with arrangement clips. when you click it off, you only hear arrangement view clips.