Engine peta/coverl nozzle question

Are there any sources out there on why certain engines seem to use one nozzle petal/cover solution and other engines another.
Engines such as Snecma M53 and M88, WS-10 seem to have shorter petals that don’t seem to close up as much as some other engines’ covers. Their inner nozzle, of course, still seems to open up and close as necessary.
There are also engines such as RR Spey and Soloviev D30f6 which seem to have completely fixed outer cover.

But at the same time there are many engines such as EJ200, PW f100, GE f110, GE f404, Saturn Al31, Klimov rd-33 and so on which have very flexible outer nozzle petals that contract alongside the inner nozzle.

Then of course there are subvariants, like the engines on most F15, featuring no outer cover/petals at all.

What are pros and cons of said solutions? Especially the Snecma m55/m88/ ws10 versus Ej200, f100, al31 and others?