ST Massacre of Luke's students

I'm wondering how many students there were? In Rey's vision it looked like there were an awful lot of bodies on the ground but I've only seen it once so I may be wrong. I wonder if they were able to put up much of a fight or was Kylo that powerful? He seemed to be the only one of the Knights of Ren with a weapon. Would Luke's students, at least some of them, been armed with light sabers - if not their own yet, at least some for training purposes? Were the students left vulnerable? Would Luke have been lured away or was part of Kylo's betrayal that he knew Luke's movements and that Luke would be elsewhere and was able to plan the attack?

 

Why would Kylo be the only one with a weapon? There was at least one dude with a blaster.

 

Pablo Hidalgo seems to be saying that the vision is not, in fact, the Jedi massacre (which I've suspected for a while).
https://twitter.com/pablohidalgo/status/682962831998730241

So I don't think we've actually seen anything to do with the massacre yet, and it's anyone's guess really how many students got killed.

 

Like grandfather, like grandson.

 

I'm wondering if any students escaped.

 

I have wondered where Luke might be during the attack.

 

I thought that scene took place among the "Clan" described in the MSW rumors, which was separate from the Jedi Temple attack. Seems that's the case. My current speculation? It's Rey's family clan that's attacked. And maybe...it's a Kenobi clan...