Byzantines: Producing Keshik via Golden Horn Tower

From my testing the Golden Horn Tower produces the same set of mercenary units as you could train from the mercenary house. For all of them except the Keshik. If you get them via the mercenary house, you get a pair of them. But the Golden Horn Tower produces a set of 3.

It does not seem like the production time is adjusted for the additional 50% value and it seems to be the only “odd one out” in this regard. (though I have not thourougly tested all trade-post units).