The best bull I've actually physically seen that was killed in the Margaret was killed by a friend of mine and was officially taped at 318" gross by Jerry Egbert (Pope and Young/Boone and Crockett club) scorer. He was a beautiful black horned 7x7. In fact he's a member of this site (rewipe). That was pre-indian hunting massacre. At that time late 90's Jerry hadn't taped any bulls out of the margaret that scored better. Not that there aren't any 300" bulls left in the Margaret, there just few and far between. I know of another 6 or 7 hunters that have drawn margaret and have tagged out on rags, a couple of decent 5's, two small 6's and a spike. Margaret has the age class just not the genetics to grow big bulls. With it's age class there should be a 350" being pulled out every year, just doesn't happen without genetics, needs some Hanford bulls blood introduced.

If I had drawn Multi-elk I wouldn't even consider westside for an opportunity to tag a 300" bull, I would be all eastside on my choices with whichever weapon/season that fit my schedule.
With Washington's draw odds you have to figure simple odds, draw tags divided by applicants. You can't figure in points with our system. More points help of course but if you have bad luck you won't draw, good luck you will draw.
With your time constraints of your selway hunt you have pretty much ruled out the best hunts Muzzle/Rifle Oct. 1.
So being able to bowhunt increases your odds of draw anyway and with your other hunts your only real option is eastside archery or possibly the late October rifle hunts.
Dayton, Wenaha east and west (especially having access to packstock), Clockum C and Peaches. I've drawn Peaches twice as my 4th choice. Best bulls are in the blues. That is where the governors tag holders hunt almost every year. Success rates in Goose Prairie are pretty low (9-11%). Peaches fluctuates from 15-25%. The blues are pretty much 0% or 100% success rates, due to low tag numbers 1-8.
The only way I will apply for Margaret is if I am hunting wetside, like this year and then it will be 2nd choice!
Sounds like you got a great season planned. Did you put in for Idaho's controlled deer/elk hunts?