Here's what I do. When I go to the page with the text window for adding a reply, I scroll down and look at the most recent post to see if anybody has already responded to the name I'm planning to respond to. If not, I'll add my post (quickly). After I post, I scroll up to see if anybody slipped in ahead of me. If so, I'll either edit or delete my post. It's just a matter of courtesy.
That said, it's no big deal if people don't follow this advice.