Thanks again, Walter, for confirming that there is no explicit discussion of astrology as an (in)accurate reflection of karma in the MU. Astrological texts repeatedly assert that the function of astrology is precisely to make the workings of karma visible, e.g. Vṛddhayavanajātaka 1.3:

yā pūrvakarmaprabhavasya dhātrī dhātrā lalāṭe likhitā praśastiḥ |
tāṃ śāstram etat prakaṭaṃ vidhatte dīpo yathā vastu ghane ’ndhakāre ||

'This science reveals the edict carrying the impact of previous action, which was inscribed on one's forehead by the Creator, even as a lamp [reveals] an object in utter darkness.'

Ideas of a predetermination in the sense of “effort 1” (past) controlling “effort 2” (present) are lacking.

In consequence of that the result depends solely on the superior fighting power in the hour of clashing interests. When it comes to that, the stronger (atibala) of the two will succeed (√ji).

Yes, I did get that point, which is why I specified 'In the case of a person who is not willing to make any great effort'.

Best wishes,
Martin