If you really want to know about line arrays, I think the White Paper by Dr. Christan Heil is still available from L Acoustics. From it you find that line arrays are very complex and not just speakers in boxes hung vertically. Very specific rules have to be followed. For it to even start to work as a line array at frequencies into the mids and lower midrange, it must be 2 or 3 meters or more (more is better) in length. Even long line arrays don't work as "line arrays" at all frequencies, and curving the array more than a few degrees destroys the line array effect. There is nothing wrong with building your on speakers, but leave line arrays to the professional manufacturers.
There were a couple good white papers on JBLpro.com but they seem to be missing. One that gets into the differences between point source and lines:
https://jblpro.com/en-US/site_elements/line-array-or-point-and-shoot-speakers