if the hive sword bearer is out too long, crota is going to move. he has to go down quickly and then your sword bearer has ro hurry into position to callout when they're ready to jump. DPS/shield break on crota doesn't start until they're ready to jump. as soon as you start firing at crota, sword bearer should be making their way onto the platform. after the attack, DPS waits 2 seconds as he's standing up (he's immune right now so don't waste rockets) and then fires at him again to get a second hit. sword bearer should still be near crota, but not directly under him (unless they have camo). you can get two hits doing it this way, but it's all about the timing. sword bearer has to give the call.
when crota moves, he tends to slow down in the middle of the bridge if he's aggro'd to the sword bearer, so you can still down him and avoiding wasting a strike (unless the sword is already spent)
it's not "easy" until everyone is on point, but the only one exposed to much risk is the sword bearer.