Those 2x2 AESA plates should be stationary apart from launcher. This economical solution would allow use larger plates.
Purpose of having 4x AESA radar( or independent search / tracking radar) on a CIWS or PDMS is to make it fully autonomous so that it will continue to function once integrity of the ship is lost.
If you install 2 x 2 stationary AESA radars, then there would be a need for dedicated tracking / search radar (like the one on Korean CIWS) on the CIWS / PDMS.
In my opinion Aselsan's configuration stays in a good place its range (to be disclosed) and IRST capability and affordable so it can be doubled.
Optionally those 4x radars maybe installed on a seperate mast with a direct link to CIWS's own controller. But distributing these radars around the hull would require either a seperate controller to merge the images or to make it go through the CMS, again remember these systems are made to me autonomous and function even if operations room or the bridge is lost.
Installing 2x means those are made to function once another half of a ship is totally lost (see for example radar installation in newer destroyer designs). Once another half of the ship is lost then the PDMS will be blinded at a sector. In fact, PDMS can fire at blind section by avoiding the no-entry zone (indirect shoot).
I can further tell this; TN wants a fully autonomous PDMS (similar to Goker) on a platform to be equipped with rotaring type AESA , 2x Traking radar and 3x IRST. They are not worried about increasing the cost by having 4 extra small AESA on the PDMS, for sake of increasing survival rate.