so the fleets look like
SSF
2 x Flotilla of Type 054A (568-571) and (572-575)
total 8 ships
ESF
1 x Flotilla of Type 054A (529-532) and Type 054 (525 and 526) plus they will get 2 more Type 054A (548 and 549)
total 8 ships
NSF
1 x Flotilla of Type 054A (546,547,538 and 550)
total 4 ships
which gives total of 20 frigates (18 x Type 054A + 2 Type 054) or have i just totally messed this up!?
No, you did not mess it up. It is more or less also what I believe. They form frigate squadrons, though, subordinate to destroyer flotillas:
1 Destroyer Flotilla Qingdao: 538, 546, 547, 550
2 Destroyer Flotilla Dinghai: 525, 526, 529, 530,
6 Destroyer Flotilla Dinghai: 548, 549 (both commissioned), 531, 532
2 Destroyer Flotilla Zhanjiang: 568, 569, 570, 571
9 Destroyer Flotilla Yulin: 572, 573, 574, 575