This recent post, Edit history shows an edit that I can't see on the question, and this from a couple of months ago, https://stackoverflow.com/posts/19760375/revisions, show that there are some problems when there are simultaneous edits to the same post.
I had a confusing edit the other day, the confusion arising because the OP was editing at the same time, so my nine-character change turned out to be less than six characters, and I had to hunt for a few more things to edit. This particular edit I made within the five-minute grace period after a question is posted (so I avoid editing during that time now).
Today, I have another variety.
Whilst reviewing this, https://stackoverflow.com/review/suggested-edits/3852133, and attempting to Improve (not sure how that should work, but I couldn't do it) by the time I gave up and Rejected, the Edit had been Approved. Off I went to edit the post itself. I made the change, saw my name as the last editor and for some reason looked at the edit history.
There was I, but no changes, and there was an edit by one of the Approvers, who had perhaps had an attack of conscience (or couldn't work out how Improve works either) and fixed-up the post by removing the thanks.
There are some rough edges when there are simultaneous edits, mostly the consequences have been minor, but get three people doing different edits and quite a pickle might ensue.
Is there some sense in preventing other users editing during the grace period (I see that a lot, even with the small number of reviews I'm doing whilst the Edit Review is so frustrating)?
I've suggested a longer period previously, and comments to the OP that an Edit is needed (this was not liked, which is fair enough).
Blocking edits for the grace period would also reduce the confusion of the instant answer, near instant edit to fix a typo, and then comments-clash about whether an answer is appropriate given the question that has been asked (subsequent to the edit).
From reading, it seems that simultaneous edits are resolved in favour of the more substantial (characters) edit (I hope it includes markup). Little things are going wrong. If a post is actually pickled someone will likely notice: is that sufficient reason not to smooth off some edges with any simultaneous edits?