Of Aspect Warriors and Exarchs

So, I'm looking through the CWE codex and I'm struck by something. Is there any reason, any reason AT ALL, to NOT take an Exarch?

They cost the same, and give you an extra wound and attack to boot.
There's no lost Wargear, or increased Wargear cost as the upgrades are always optional.

So why is it an option? Fluff?

And why, WHY, would you, as a player, ever take the option of 'I want this unit to have 1 less wound and 1 less attack for the same price'.

Anything from the crowds?

My only thought might be that if you're taking several small squads you might not actually have enough Exarch models. Other than that, it seems a no brainer.

Count Adhemar wrote:

My only thought might be that if you're taking several small squads you might not actually have enough Exarch models. Other than that, it seems a no brainer.

But even if you don't have enough Exarch models, just say that they're carrying the same gear and use some other indicator (something on the base, a specific stance that you've split the MSU up into appearing only once in each unit, whatever.

Anyway, glad to see I'm not the only one confused by this.