I think you aren't getting my point.
Damen is marketing its ship as an OPV.
Swift 75m corvette can do the same duties in peacetime but as the MN article states... is an ASW corvette in wartime.
If PN wanted more OPV's, it could have just ordered 2 more 1900t OPV's.
Basically, PN is getting 2 (with option of 2 more) cheap ASW/AShW assets... which though not as good as Ada can data-link with Orions, ATR-72 and possibly the Ada itself.
I understand that those are cheap vessels.. but PN could make those quite capable with little added cost - say adding US/Swedish torpedo, Phalanx, Harpoon and even some sensors from two retired Type 21's.