I honestly think that middle ledge is how bungie intended crota to be fought from. Think of it like the VoG, the VoG middle platform with the relic shield ability makes total sense in bungies eyes. Why would the make the ledge big enough to fit probably like 15 guardians if they didnt intend on us using it? Why would the make it where the middle platform is 'just' a bit out of the reach of the boomers? Why would they make it where the two pillars in front of the middle ledge are also out of boomer and crota reach? This I believe was Bungies vision on how to defeat crota. Not dipping in and out of the left stair case. Also why is it that it takes 3 swords (if you do 2 takedowns per sword. I understand you can do 3 takesdowns in which only 2 swords are needed) on hard to kill Crota and by using the middle platform you can get exactly 3 in without a timed enrage and you cant get 4 in before the timed enrage? This middle ledge is there for a reason, just like atheons middle platform.