yes, the ac from one level of monk is usefull... if you aren't using the armor mod pack that adds damage reduction to armor.
then, even the bonuses from AC from monk IMO don't outweigh the advantages of damage reduction and specials provided by armor (which incorporate on shift, btw).
the other thing is that it of course requires a lawful alignment type to have monk as a class, and I just hate the idea of a lawful druid.
as an experiment, I tried this combo in HOF and found it to be extremely powerful:
druid 21/ monk 1 (removed the alignment restriction)/ cleric of Demarch of Mask 8
I agree that the 1 level of monk adds evasion and AC bonus, or you can put on some armor for the armor's abilities and damage reduction. Demarch is a good rp choice (neutral), and also gives mirror image as a domain spell at level 3!
OK, so if you're using the druid shapeshifter mod, that means you can be a chromatic half dragon pumped up with trollish fortitude and all the lower level cleric buffs, plus mirror image.
talk about a tank. add all the major druid spells you can cast on larger groups before xforming, and there really is little that can stop you. "free" healing with the dozens of lesser shift forms as well.
you will start getting the 20% xp penalty when you hit level 3 cleric, but it's only a minor inconvenience.