Realised I did not answer the question that you asked. During Buddha’s time, the monks were given specific meditation subjects that suited their temperament. And within a short period of time, ardent and resolute, the monks could attain arahanthood. Now that the Buddha is no longer around and there is no one else who could read our citta with high precision and advise us on a meditation topic to undertake, the safest way is to follow the materials on Lal’s website (my personal opinion). The materials on Lal’s website are presented in a very systematic, sensible way which cater for a wide range of readers. And it is by far the most convincing Dhamma materials I have come across. I have read many Dhamma books written by many Bhantes. Some of which do not match my personal experience and some are just doubtful to me. One such Bhante who said to become an Anagami or Arahant, one needs to attain the Fourth jhana (Bhante did not specify ariyan jhana). Nothing short of that standard. But this contradicts to some suttas which mention that some people could also attain Anagami and reborn into the Pure Abodes just by attaining the first jhana (ariyan one of course). I forgot the sutta reference as Suttacentral has a new format and all my favourites from Suttacentral are rendered useless already. Anyway, this particular sutta is a conversation between a Venerable Ananda and a disciple. Also, there was a very gifted disciple of Buddha whom the Buddha proclaimed him to be fastest to attain arahanthood. He only listened to a short stanza from the Buddha and almost immediately attained arahanthood, but was gored to death by a bull (disguised by a demon) on his way back home. Within such a short time, it is highly impossible for someone to attain the four jhanas. Moreover, this arahant was walking! I have never heard of anyone who can attain the fourth jhana while walking. During the 45 years of the Buddha’s teaching ministry, the Buddha travelled to many places to deliver His teachings. Is it not possible for any one disciple to listen to the Buddha’s discourse all the time. Many would have passed on way before the Buddha entered into His final years. Which means many disciples did not get to listen to some discourses which were uttered by the Buddha, and yet they could attain liberation. So, in my personal opinion, it is not mandatory to listen to all discourses from the Buddha to attain liberation. Modern technology has allowed us to have this privilege of accessing all the suttas in the internet. In a way, we are more fortunate than those disciples during Buddha’s time. I think there is no fixed curriculum to follow in Buddhism. That’s the reason why we see many sects surfacing, each having their own views and doctrines. We have to be careful who we learn Dhamma from.