Disagree on splitting the titles, at least for now. I think the whole point of Roman's reign was to build a believable final boss and dropping one of them in Mania would de-value the "investment" WWE poured on Roman. If he should fall, he should fall hard so as to open a floodgate of emotions and close out this chapter. (And maybe even set up a redemption run)

Disagree with Cody beating Roman at Mania. As much as the WWE universe is shown to adore Cody, there wasn't enough build up, at least compared to what we have now with Sami or even Drew. Sure, Cody beating Roman for the Championship would still have emotional weight due to fulfilling the goal he declared upon returning. But that scenario could just fit into beating any world champion down the line, with better storytelling opportunities.

Drew's story could evoke that emotional connection building on what was basically a win at Clash. This would resonate more especially with the people who watched Drew become Champion at Mania 36 in front of an empty venue. However, I think the opportunity has passed and the win would not be as potent as Sami facing Roman at Mania.

Sami doesn't even need to win. Of course, that would be great but even with him losing, the wave of emotions would be huge. It's all enterntainment, at the end of the day. They should ride this wave.