Considering the ABe 8/12 class set the gauge speed record, they probably have the power to spare. If it doesn't complicate things like gearing too much, it makes sense to build in power to go fast or heavy.

I love to see a mixed consist like that!

https://de.wikipedia.org/wiki/RhB_ABe_8/12
https://en.wikipedia.org/wiki/Rhaetian_Railway_ABe_8/12 -- The tractive effort and power output numbers say they are no wimps: 280 kN / 58,450 lbf and over 2300 kW / 3000 hp continuous.

Odd factoids about the Allegra, gleaned from the German page:
Each end car has twelve first-class seats with only a glass wall between them and the driver.
All of the pantographs sit on a common bus so the AC pantograph can substitute for a failed DC pantograph.
The maximum hook load on the Bernina line was raised from 140 tonnes to 160 when the Allegras came into service.

http://www.railpictures.net/showphotos.php?locomotive=ABe%208/12

>>132200 -- I think you will like http://www.railpictures.net/viewphoto.php?id=555244&nseq=21 showing two Allegras, one with four coaches, the other with three coaches and five empty cans.