#2 Lashley's not Universal Champion material, at least right now
Bobby Lashley is a physical specimen and a special athlete. He's achieved much success across two realms, something not every man in existence can honestly boast of. But yet, I do not think he's ready to be the face of RAW just yet, right now.
Brock Lesnar brings a special kind of aura with him when he steps into the ring because of the mystique surrounding him. Much of it also has to do with him not speaking, and letting the greatest orator of our time, Paul Heyman, hype his matches up while Lesnar cracks a smile and jumps around. Lio Rush is doing a commendable job but he's not Paul Heyman yet.
I guess Lashley will become a monster in his own right when 2019 comes around, but for now, he's not a believable Universal Champion. Maybe this big match will take place later, rather than sooner.