4th edition hidden rules and artillery recon

[Hugmenot]

If you want to set up units hidden in a town, the spotting range shrinks from 3 hexes for limiting terrain to adjacent spoting only. Once again a tremendous advantage for the defender or the attacker waiting in ambush.

The range for hidden units in limiting terrain was also 1 hex in 3rd edition rules. See 16.6, second paragraph, for the details.

Recon by artillery seems to be a compensating mechanism for the new hidden unit optional rules.

Hidden units is not a new rule.

As others pointed out, there is nothing in the Optional Rule preview which states hidden units must be revealed if they suffer any adverse result.

As Recon by Fire can be used against units on the board that are still unspotted, I doubt it was created specifically to counter the advantage of having hidden units. I would probably use Recon by Fire against known (but yet unspotted) units on my way to an objective with the hope of weakening them before engaging them.

As Recon by Fire will usually favor the attacker when victory conditions include taking terrain defenders can set up into, I am unlikely to use this optional rule without also using another optional rules which favors the defender.