Reordering chunks in a trigger is a frustrating experience (usually when there are large statements). Statements will fly to the top of the modal with reckless abandon, but then refuse to move downwards no matter where I put my cursor. Then when they do move down, they move at a snail’s pace, and I better be paying attention when other statements pop up so I don’t miss accidentally putting it in the wrong spot, lest I have to send it flying back to the top to try again. 
One thing we use in our apps for re-ordering is a simple Up / Down arrow set - click the thing, click the arrow, ???, profit. Not saying it needs to be done that way, but I’d much rather have to click an arrow a few times and know it’s going exactly where I intend it to go each time, even if it takes a couple clicks. Click and drag is great when things are small, so maybe just adding it as an option.
. I can’t promise any immediate changes but we are looking into this and other user experience improvements related to triggers. If your interested we’d love to talk to you about your experience. Feel free to