The newly added ASM-1 and ASM-2 missiles suffer from several issues, most notably its inability to actually hit targets in the end, often skimming right over the target warship entirely. This issue is something I assume is, or will be noticed and fixed by simply making sure it dives right before impact, or make it skim lower in altitude or something in between (like getting lower as it locks onto the target).
Additonally, it is likely that the warheads mounted on the missiles are inaccurate. During testing, a single ASM-1 was able to sink the target ship (A tacoma-class frigate) with a single hit to its stern section, though it took 2 days for flooding to finally cause the ship to capsize. Now this alone proves that the missile should be able to properly hit such ships with decks so low to the waterline, along with proving its power. The warhead weight is commonly listed at 150kg, over thrice the mass in-game of 47kg. Unfortunately, I am unable to find any source backing up the 150kg claim. Though on the other hand, the dimentions of these missiles are similar to that of the air-launched variants of the US Harpoon missile, which has the warhead of 221kg. Finally, the ASM-2 has an identical warhead to the ASM-1 in-game, though various sources make it clear that the ASM-2 has an upgraded warhead.
Another issue is exclusive to the ASM-2. It should have BOL (Bearing Only Launch) feature, which allows it to be fired essentially as an unguided rocket until it spots a target by itself.
Source: 技術研究本部50年史 P196-198