F-18 stealth weapons pod ( EWP )

http://defense-update.com/20130830_semi-stealth-advanced-super-hornet-completes-first-phase-of-test-flights.html#.U_Kgo8VdWbM

vs

so basically each pod can hold 4 aim-120 ( 2 time more than each f-35 internal bay, and four times more than each f-15SE internal bay ) , or each pod can carry 6 SDB and still have space to carry 2 Aim-120 ( alot more than f-35 , f-15SE can hope to achieved with each weapon bay )
how come the small pod can hold so many more missiles and bomb despite f-35’s bigger weapon bay ? , why didnt LM design their fighter weapon bay the same way ( seem alot more effective ?
http://snafu-solomon.blogspot.co.uk/2013/08/f-18-pod-carry-weapons-graphic.html
can other fighter use the EWP or that only for f-18 center station ?