Mavericks are not acutally design for anti-ship roles. In fact,
only the G version with a slightly longer range has been built for
use against ships.
Mavericks also have a relatively short maximum range, approximately
25KM from a high attitude launch. Harpoon on the other hand can
reach approximately120KM on a sea skimming attitude. Thus, you tell
me Mavericks are better? How can it be? The Skyhawks and Vipers
will have to be within the Seawolf SAM range to launch a Mavericks
whereas a Harpoon launched by the Fokker or Viper can be as far as
50 KM - way outside the Seawolf range.
The only reason I suspect RSAF chose to use Mavericks in the past
and only recently started to use Harpoons is that the theatre of
anti-surface operations were pretty much limited to Straits of
Singapore, Malaysia and possible just the Southern most of the
South China Sea. RSAF and RSN has extended this radius to somewhat
bigger, and thus having a long range OTH anti-ships missiles make
sense. Harpoons are a lot more expensive and the Naval vessels
already use them, so air launched version were not so much
needed.
Penguin ASM would have been good. Singapore in fact tried to
acquired them but were blocked by the Norwegian govt. Couldn't even
purchase an American made one without Norway's approval. the Mk3
Penguin, like the ASM Maverick, uses an IR seeker rather than an
active radar with OTH datalink like the Harpoon or Exocets.