This isn't the case, I just verified it. A test.html page with <script src="dummy32k-a.js"> and another for dummy32k-b.js show as downloading concurrently in ch

This isn't the case, I just verified it. A test.html page with <script src="dummy32k-a.js"> and another for dummy32k-b.js show as downloading concurrently in chrome devtools network timeline. It makes sense since the HTTP fetch order doesn't affect semantics as long as you obey the execution order from the page. Unless you're doing something very contrived, such as serving them as no-cache and generating different js dynamically from server side if a previous script has been requested...