If there were trouble, or confrotnation, this is what Singapore would have to face other surface combatants and subs with, so comparing them is not out of the question.
The Aster 15 has a range out to 30 km, so although it is not nearly as long ranged as the SM or the HQ-9, it does have effective engagement envelopes down to sea skimmers which the HQ-9 is lacking. And the Formidable's combat systems are effective...at least the equal IMHO to those on the Lanzhou Type 52C DDGs of the PLAN.
Anyhow, all in all, I believe the Formidable to be, short of the major AEGIS class DDGs, one of the most advanced and capable vessels in the western Pacific, despite its smaller size and compliment. At 3200 tons it is a very effective and capable FFG, and would have to be taken into serious consideration by any nation contemplating any action that might require confronting them.
I was thinking that maybe the exercises came under the “Aegis” of some treaty organization that doesn’t have Britain as a member - but I’m sure there could be all sorts of alternative
explanations. Maybe their recent change in government?