I was in the local MUP and a hulk of a guy rides past me, big gearing it, riding at a good clip. I got on his wheel and stayed there. No way was I going to be able to pass him. After a few miles we come to a road crossing with a traffic light. Talked to him a bit. He was in the process of getting a position at the local fire department. Complimented his riding and he mentioned his father was a cyclist back in the 70's, raced, and was State Champion. Asked his father's name and he told me. Said I raced with his dad back in the day. We had a great conversation.
Every situation is different. Trade off the lead. Draft a stronger guy for a long time. For me its usually, " I'm cooked, I'm going to just sit on your wheel".