Most will say 1-10, but you can also run the 1-11 quite easily also. That is the go to twist for the WSMs with 210s so sure the win mag will run them also.
I've never shot a 200gr bullet out of 1/11 twist barrel so cann't say how the velocity compares to the 1/10 twist barrels. Years ago build a 30-338mag (338mag case) used a 1/12 twist barrel just to shoot the 165gr bullets later had another one build used a 1/10 twist barrel for the 180/200gr bullets.
Had a 30-06 with 1/10 Kreiger barrel and it was alittle faster than the 1/11 twist barrels (Lilja/Bartlein) using the same loads 180gr bullets and the 1/11 twist were faster with 165/168gr bullets.
I'm always playing around with twist myself I'd use a 1/10 twist for the 180/200gr bullets. Well good luck