make sure you have at least 1 hide per scorp and then a couple extra to avoid any potential territorial issues. Also introduce them all at the same time. Don't put a couple in and then a little later put a couple more in. If you put them all in (one after the other is fine) at the same time it is new to all of them and it should minimize any squabbles. Also make sure they all get fed regularly, I know this is common sense but it is especially needed in any communal set up. If the scorps are not hungry all the time they will not contemplate eating a tankmate. You still need to watch for territorial issues though. I have seen a lot of communal set ups with these and the 4 juvi's I have are all together and doing great. I do keep other species communally as well and some of these principles go pretty much across the board with any communal species.
As commented on the other posts, use a heat mat but put it on the side of the vivarium and if you need to use a lamp to keep the heat up that is fine. The mat will not dry the vivarium out as fast. I'd also recommend doing a false bottom set up if you have the space. Even if it's a smaller amount of gravel. I have a 1.5" or so of medium aquarium gravel down and in the corner I have a gatorade bottle hidden in some bamboo that I cut the bottom off. I can then unscrew the cap and add water directly to the gravel not over saturating the substrate. You will still need to mist a bit but this will help keep humidity up and also for a burrowing scorp it will be a little more natural in the sense that the deeper they burrow the more the moisture increases, they will be happier being able to burrow to their desired condition.
With the high humidity watch for mold though, I have had problems with hides and other wood pieces i have put in my tanks and have switched to all driftwood as it is not as susceptible it seems.
Good luck and post some pics up
I have 3i or so babies too. Was going to get 2 adult females but they were out and only had males so I got 4 babies instead. Anxiously awaiting them to grow
BTW I didn't put any mesh down between the gravel and substrate, I was worried about burrowers getting trapped. It doesn't seem to get too dirty yet either.