What makes you think the T-50 can carry more than the F-22, J-20? I don’t see any stores attached to any of the prototypes.

Let’s assume that internal capability of PAK-FA and F-22 will be exactly same, although most of hypothesis is that PAK-FA is larger.
Then we can see that no less than 6 hardpoint for PAKFA and only 4 for F-22.
The inboard pylon under wing for PAKFA are supposed to carry two 3000L DTs, left 2 outboard pylons for big-sized weapons like Kh-58 or something else.
However, F-22 are supposed to carry 4 2200L DTs with 8 a2a missiles underwing, now we can see only 2 to be loaded in reality.
Even, outboard hardpoint for F-22 still available, 3000L DT is not proper for F-22, therefor, the loading flexibility of advantage are on PAKFA’s side.
If PAKFA also loads 4 DTs with 8 missiles underwing, there are two hardpoint under inlet remaining for large-sized weapons like Kh-31, so PAKFA still gain advantage against F-22.
J-20 has no certification at because it even inferior than F-22 for external loading.