Drew McIntyre is a big, scary, bearded man.
Braun Strowman is a big, scary, bearded man.
They are both absolute studs, two raging bulls that can talk the talk, and walk the walk.
The two are very similar, and yet, extremely dissimilar.
They are both physically imposing, and both have an aura about them. They carry themselves like they would rip someone limb from limb, and look like they'd have no trouble doing so. Their fates are currently intertwined in their quest to destroy the Shield. Currently, Braun Strowman is clearly the alpha male, but that is unlikely to be permanent. Drew McIntyre is clearly being primed for a monster push; one that will see him lose the dead weight that is Dolph Ziggler, and could see him usurp Braun Strowman as the top heel in all of WWE.
While their similarities make both ideal candidates for the position of the top heel in all of WWE, it is their dissimilarities that make McIntyre a more compelling option than Strowman. The argument that McIntyre is a better choice than Strowman has as much to do with McIntyre's positives, as it does Strowman's negatives.
When it comes down to brass tacks, this discussion hinges on the characters of Drew McIntyre and Braun Strowman; their motivations, their history, and the emotional connection they have with the audience. I believe that Braun Strowman's character does not lend itself to being a long-term top heel and that Drew McIntyre's character is ideally suited for such a role.
#1 Braun Strowman's character is a bit cartoonish
Braun Strowman is extremely entertaining.
But, he is also too cartoon-ish. Everything popular about him; his mannerisms, his stunts, his signature taunt, is over the top.
Drew McIntyre, on the other hand, is a more legitimate, believable character.
While Strowman is outlandish, McIntyre is intensity personified.
Strowman yells with his arms in the air, flips over cars, and once impersonated his imaginary twin brother.
McIntyre smolders, challenges people to hit him, and then beats them up.
One of these is not like the other.
And only one of them screams "top heel".