The Perry Class frigates, out of the 1970’s were good anti submarine platforms (they were designed with one key mission being to get US reinforcements to Europe in the face of Soviet subs), with some anti air defense, helicopters(anti-surface, and anti sub), and a 3 inch gun. It was built to typical naval construction requirements and demonstrated (USS Stark) it could take major missile hits, as in PLURAL and survive.
The LCS a VERY fast ship was designed to have ‘modular’ mission payloads swapped depending on the mission at hand, including mine sweeping (the payload for which is not deployable yet), has helicopters and a 57mm gun (~2 inches) and NOTHING else. Experiments are ongoing to equip the LCS with some anti air and short range anti ship capability. The LCS is aluminum hulled (weight) with steel both in contact with saltwater, and already have shown corrosion issues over dissimilar metals (a problem which any chemist could have told Austal and the Navy, cannot be avoided unless well planned for). They are not thought to be able to take a hit and continue.
Today the anti air mission is conceived to be a defense which may have to be against a saturation attack (many missiles and planes). The FFG-7 Perry’s have (if they are still so armed, some of them are not) a single arm missile launcher (for SM-1 missiles) and old radars.
This is where worry over the F-35 reasserts