wouldn't number 2 then be whichever one is not #1 between emperor and temensis? lol just teasin ya I've heard some people claim that umbee can grow as large as dovii but the consensus is that dovii can typically grow larger. I'd love to see an umbee that's pushing 30"...but then again I'd love to see a dovii that size as well. lol
that's a complicated question because, given the right size aquarium, they should be able to reach the same max size as they would in the wild. However that tank size would be huge, possibly over 1000 gallons so it's hard to say.
Most people say they usually max out at 18-24" in aquaria but that's going to be because most people can't provide the right setup for them to reach full adult size.