Question about mercenaries and the EDU

A quick question about the EDU. Occasionally a unit appear twice in the EDU, once as a standard version, the other as a mercenary unit version, both having exactly the same name and stats (example: #152 Hippeis Thessalikoi and #153 Hippeis Thessalikoi (which is a merc unit)). I understand that a unit with the 'merc' identifier can be recruited as a mercenary unit, but what baffles me are the following two issues:

1) Why do we need two versions? Wouldn't it be better to use the slot for something else?

2) How does the 'ownership' issue work with these? I though all mercenary units could be hired by all factions, so why does the mercenary version have a different ownership from the standard one? And how does this affect things? (In the above example, #152 can be recruited by Epeiros and Makedonia, while #153 can also be recruited by Koinon Hellonon, though I have never seen that happen (unless I hired the merc unit))

I am asking these questions because they will allow me to understand recruitment better for the purpose of including it on my cards.

I believe this is because of model-sharing issues. I think we have to do this occasionally because otherwise a faction couldn't recruit the merc without getting a CTD. In such a case where the stats are identical, you don't need to bother with making two units - they are effectively the same thing.

Ok, thanks for the explanation, that now makes a lot more sense!

Although, to be honest, I swear I compressed 152 and 153 to one, as you are right in that instance, it is not needed.

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