Good observation.
Fundamental Concepts:
A set of cetasika arise automatically according to gati/arammana. There are 52 cetasika, but 25 are good (sobhana) cetasika that arise with “good gati” and 14 bad (asobhana) cetasika associated with “bad gati.” Six cetasika may arise with good or bad gati, and seven “universal cetasika” arise with every citta.
– Two of the universal cetasika — vedana and sanna — also arise according to one’s gati; the other five are “managerial cetasika” doing various functions; cetana is one of those.
– Thus, cetana is a universal cetasika in EVERY citta. It is the cetasika responsible for putting together all relevant cetasika ACCORDING TO one’s gati and the particular arammana (sensory input.)
– Cetana does its work automatically, within the rise of the citta (< billionth of a second.)
The initial set of cetasika arising in response to an arammana define mano sankhara.
- If the mind attaches to that arammana, it may start adding more good or bad cetasika while doing vaci sankhara.
- That process may be intensified with kaya sankhara.
See "Cetasika (Mental Factors)” and “Saṅkhāra – What It Really Means”
– May be I should write a post on those connections? The above two posts may not show the connection.