Why five aggregates instead of just three?
Very good question, which i imagine i will post more about at a later time.
Firstly, about the translations, I suspect the translations of &quot;paññāpeti&quot; as &quot;delineate&quot;, &quot;describe&quot; or &quot;declare&quot; may possibly be questionable. &quot;Paññāpana&quot; (from &quot;paññāpeti&quot;) is found in SN 22.82 and taken by Bhikkhu Bodhi to mean &quot;manifestation&quot;, which fits the context of SN 22.82. Therefore, substituting into MN 43, it might read as: ???????
Secondly, the three types of feelings are related to the arising of the three types of defilements, such as explained in paragraph 30 of MN 148. Therefore, it appears most essential to highlight the feeling aggregate. As said in paragraph 15 of AN 3.61:

Now it is for one who feels that I proclaim: ‘This is suffering,’ and
‘This is the origin of suffering,’ and ‘This is the cessation of
suffering,’ and ‘This is the way leading to the cessation of
suffering.’

Again, AN 10.58 says:

vedanāsamosaraṇā sabbe dhammā
All dhamma practices converge/meet on feelings.

As we understand by MN 148, MN 38, MN 37, AN 3.61, etc, feeling can arise without there being the arising of craving and suffering. Before the Buddha, I imagine people were seeking a nirvana that was without feeling. Even today on the Buddhist internet, we witness individuals posting obsessively and mistakenly about the cessation of perception &amp; feeling as though it is Nibbana. But the Buddha declared the only possible here-&amp;-now Nibbana and Liberation cannot be without feeling. Therefore, it appears essential to the Buddha-Dhamma, as already explained, to highlight the importance of feeling.
Also, there are conscious experiences that are predominantly feelings, such as jhana. While consciousness arises &amp; lands on such pleasant jhana feelings, obviously the feeling aggregate starts apart in and dominates such jhana consciousness.
Thirdly, as for &quot;perception&quot;, at least in relation to what is 'supramundane', there are many suttas about perverted perception and enlightened perception, such as AN 4.49 and AN 10.60. Therefore, it appears to highlight the perception aggregate is also important and it needs to be distinguished from consciousness and feeling.