ALHAT/LVS problem seems to be the overly broad requirements, it's overengineered (hence the modularization in LVS) which led to long delays during the developme

ALHAT/LVS problem seems to be the overly broad requirements, it's overengineered (hence the modularization in LVS) which led to long delays during the development. For comparison, Chang'e 3 TRN solution was dead simple, it was roughly speaking a webcam combined with the specific lighting angle during the landing. Then they iterated on it in subsequent missions, creating a decent system that was less dumb and restrictive than the original.