This has more to do with the way the radar can find, track and engage the targets rather than the missiles themselves. S-300 and S-400 uses the same group of missiles 48N6 and 40N6 family but the big difference is the radars, the S-400 batteries are using AESA radars, which also includes UHF/VHF long wave AESA while S-300 family are PESA.
Since HQ-9, S-300/400, PAC family are using TVM and SARH, your effective distance has nothing to do with the missile's kinetic performance but how far the radar illuminating beam can travel. So even if the missile itself can travel 200km, if the radar can only engage and illuminate certain targets from 125km, then that is the effective range of the missile. That is why the literature uses slant range, which you will also note for HQ-16 and HHQ-16.
The S-300 and S-400 family uses big radars --- Tomb Stone, Flap Lid, Big Bird, Grill Pan --- are considerably bigger than the PAC's MPQ-53 and the AEGIS SPY-1D. Flap Lid is said to have over 10,000 elements.
FD-2000 is said to use HT-233 or H-200 engagement radars. I don't know the number of elements, I remember reading 3,000 in one article, 5,000 in another. I think the earlier version of the radar might have been a PESA (see Carlos Kopp article), but it may have shifted to an AESA later on, to match with the Type 346. The performance quoted is tied with the HT-233 or H-200 radars or at least to what they are allowed to export; don't know if this applies to later versions with AESA and/or domestics version. It may probably not reflect what's on the Type 052C/D or Type 055, as I suspect not only do they have their own performance parameters, there might be progressive versions of the Type 346 as well.
But of course, once the missiles get active guidance, with emitters on the missiles themselves, no need for shipboard illuminators, has the ability to engage targets beyond the horizon, then the effective range of the missile becomes more of the missile's flight and kinetic performance.
