I personally do not use the ticketing system for my judgement call in quality, it’s an evaluation of scope and scale only to me.
For example, Tokyo’s Hunny Hunt is largely better than what many would consider E-ticket attractions, but to me it’s a D-ticket. It’s a wonderfully gussied up and supremely well done fantasyland style ride, it’s a bit longer than the bus bar rides (mostly C-tickets), but it’s still only four minutes and more of a medium scale. This seems like blasphemy to many, but when the 8 minute long beauty and the beast opens with a similar ride system next door, people will realize the scope and scale is different. Heck people may still even prefer Pooh, but it’s still a D-ticket.
In my brain I then add a +/neutral/- as a partial quality call.
Pooh’s Hunny Hunt is of an illustrious category of D+ tickets. There aren’t many, just like there aren’t many E+ tickets. This allows Pooh to be a leading class example without burdening it to the same standard on other E-tickets.
So you might call Haunted Mansion/POTC an E+ as different leading examples in their class.
So semantic aside, the scope and scale of Smugglers run is still an E-ticket. But for some here the differentiator is whether it’s an E or a small group might say E (minus)... but it’s still an E-ticket for scope and scale.
Roping it back in, Mickeys Runnaway railway is actually bigger than Mystic Manor and has more scenes. I suspect it may run longer than 5 minutes too. It’s easily an E-ticket. That doesn’t mean people may actually like the end product, but it’s a relatively large attraction occupying a large show building.