Historically, I would agree with you. Wiki does not have anything recorded for a seperate subspecies of african eles that existed only in ethiopia/somalia (http://en.wikipedia.org/wiki/Loxodonta#Classification), only one for "Carthaginian/ North African elephants (http://en.wikipedia.org/wiki/North_African_elephant)" which may have been a subspecies of bush elephants. Given that its range extended down to the present Sudanese and Eritrean coasts, it is almost certain that these should be the ones being refered to. This extinct subspecies/species was indeed smaller than Indian eles.
The wiki link even describes these NA/C eles as the ones that Ptoles and Carth used in battle.
However, here is the EB description of the "bush ele". Note that they are described as larger than indian eles (which the C/NA ele was not). Also note that it says they were even harder to train than forest eles which seems like a reference to modern "bush" elephants whereas apparently the C/NA eles were likely easier to tame than forest elephants (not indian/asian ones). In any event, they are statted and modeled as if they were larger than indian eles.
Spoiler Alert, click show to read:
Either the EB guys got it pretty wrong, or wiki has it pretty wrong. I would go with Arjos' interpretation since that seems more factually accurate, but as always, the floor is open to everyone to pitch in.
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