Go for it! I've brewed several gruit ales with great success, actually call mine a "koyt" as well. I've done both hopped and unhopped, did well in competitions, etc. What was most surprising to me with my first gruit is that it turned out so tart. Some herbs (yarrow in particular I think) actually add tartness with the flavor, more than bitterness. Either way, it helps balance the ale. Sweet gale is one that you really must try. It is a lovely addition with mild character for bitterness and flavor, and unlike most other herbs, the sweet gale can safely be used ounce-for-ounce in the same amounts as hops.
You didn't list any amounts, but I would suggest doing a lot of research on how much you think you should use.... and then take whatever final number you come up with, and only use about 1/3 as much, because everybody always overdoes it, I swear to you. I don't have my recipe here with me but I recently gave some of my successful amounts on HBT.com, see below. The amounts I give already were literally already 1/3 the amount I thought I should use, but also tweaked up or down slightly based on real life experience to give a slight herbal flavor that is not so overpowering. In fact probably could get away with even less than I use, as some of my friends were like "ew!" when they tasted it, but to me I didn't mind the herbs at all. This is truly a case where less is more, and even less is even more. So here's that other article (thread was about "mead" but my post is based on experience with gruit ale, not mead):http://www.homebrewtalk.com/showpost.php?p=7489600&postcount=12
Good luck. And, be careful with that wormwood. Based on what I read, I'm afraid to use any at all, as it's super bitter and easily overdone. The other herbs will give you flavor, less bitterness, and the surprising tartness, like I said. Hope you enjoy.
EDIT: You might also find this interesting.http://barclayperkins.blogspot.com/2011/11/horst-at-it-again.html
EDIT2: Oh, and then there's this.https://www.homebrewersassociation.org/forum/index.php?topic=7816.0