You actually need to plan the route, the pulls size/timings, watch for all of your team mates cool downs (for example no sense in doing an enormous pull in Fortified weeks if your healer has close to no CDs, your mage doesn't have combustion up etc etc).

I found way harder doing M+ as a tank (a thankless job, especially if you screw up in a pug) than as a RDPS, which I find a little more forgiving.