I served on the Rodney M. Davis (FFG 60) as CICO and ASWO.
The capability for AAW was lacking and earned our “target” moniker, and yes, the active sonar sucked, but you don’t hunt subs with active sonar - least not since the 60s or so. With the passive tail and LAMPS helo we were formidable enough on ASW to win a pac fleet award in that area. Our torpedo launchers were no great threat the, but the helo’s torpedos were right on target. This was back in the early 90s since then I imagine that the passive systems have gotten better.
In addition, the rail supported launching Harpoons good enough for over the horizon targeting of ships. I would imagine that they would instead install VLS with tomahawks though the potential for canister harpoons or equivalent exists. I’m assuming that the anti-ship capability can be significantly upgraded for the islanders and the real driver is the ASW side.
The other thing to keep in mind is they are much more fuel efficient and easy to maintain with the gas turbines then the old Knox class boilers. The Knoxs (originally produced in the 60s I think?) are likely worn to the bone.
TAS can be put on any ship including a fishing trawler with a module sonar sweet, so not particular to OHPs, but point taken. However, taiwanese coord op ASW is more likely to be with fixed wing assets than organic helos.
I still think fast, ASUW focused corvettes would be a better fit.
I spent 3 wks in the North Pacific on an OHP as a Midshipman - I’ve never puked more in my life - spent a lot of time hanging from the hand cable strung across the bridge. I went into tactical naval aviation where I could handle the motion :-)