It's very generous disclosure. The total number of elements is kinda similar as what i have predicted sometime ago. The arrangement is kinda similar as Netherland's SMART-L radar where there is separation between Transmit and receive "clusters". Kinda curious tho on this arrangement. Some things i have in mind is :
-Cost savings as a HPA (High Power Amplifier) is expensive. with cost/Watt is about 15-20 USD for GaAs and 14-15 for GaN. 100 Watt capable HPA is then cost about 1500 USD. This cost make parts of some 45-50% of the entire cost of a TRM. Thus The TRM might cost some 3000 USD. 14000 TRM then makes the cost about 42 M USD. The following diagram is from book "Transmit Receive Module for Radars and Communication Systems"
That 42 Million USD basically half of the Antenna face cost. The total cost of the antenna Face would be about 84 M USD. 4 faces would make it 336M USD. Since as depicted above cost of the entire AESA radar is about 78% are antenna.. then 336/0.78 = 430.8 M USD for the full 4 Faced radars with every elements capable of Transmit and receive.
430M USD is even more expensive than Garibaldi class carrier. It was offered to Indonesia for USD 390M.
Now if not all the TRM have to transmit.. you can see the great improvement there in terms of cost.
The other reason i can think of is the long pulsewidth. You can see 1ms (1000 us) Pulsewidth.. this is very long pulse. The tradeoff would be long minimum range (as 1 us radar pulse "length" equals about 150 m) 1000 us means 150000m minimum range of 150 km, target at that distance will not be detectable for a regular radar with a duplexer e.g AN/FPS-117 which have similar modes of operation. The solution for FPS-117 was to include a shorter "cover pulse" to cover the minimum range constraint.
By having separation between Transmit and receive is perhaps one can eliminate the minimum range constraint as there would be no duplexer needed. The Receive module however might include some stronger receiver protection which can withstand spillage of transmit power without being damage or de-sensitized. Thus normal operation can be performed.
The other reason is yet another cost saving but it's the possibility to reduce the amount of digital Analog to Digital Converter needed to digitize the radar returns.