Go for the dps. If it's a melee, try to bait him into following you into line of sight so that the mistweaver comes closer to keep line of sight. This might get you into a situation where you can do quick swaps on the mistweaver. Swap back to the dps if he runs and you can't follow.
Do coordinated swaps with your healer.
Since you said you're playing with a resto shaman: While attacking the dps, have your shaman put a stun totem on top of you and the enemy dps. Then grip the MW into the stun and use remorseless winter. when the first stun ends yours should begin. Try to get a kill with your CDs, maybe have the shaman hex the enemy dps to prevent peels. If the mistweaver gets away, swap back to the dps.
The swaps should increase the pressure you do and hopefully force some defensive CDs/kill or atleast force him to use way more mana.
Try to predict when the monk will use his roll/torpedo and root him just as the animation begins. This stops the roll mid air while he still gets cooldown.
Also try to look for opportunities where the MW wastes his rolls or torpedoes for example if he rolls in to stun your healer. Swap on him then and he'll have a much harder time getting away.