देवेषु विश्वासटिप्पन्यः

Was Dumezilian tripartation really a PIE thing or overdone? It had a place in vedic & shows cognates in other IE traditions. Hence, my take is that it was an old idea present in IE tradition.

In the vedic tradition it is notably emphasized as the 3 basic vyAhR^iti-s. However, given that the tradition also records several other vyAhR^iti-s of different counts adding on the basic 3, it is clear that there were other concepts in parallel to tripartation. E.g. see: exposition of the vyAhR^iti-s.

We can also make case for some importance for tripartation, without blowing it up, via numerical analysis of the RV:

eka- 204
dvi- 290
tri- 346
chatur- 70
pa~ncha- 59
ShaT- 8
sapta- 215
aShTa- 17

Thus, violation of Benford’s law with dominance of 3 suggests that it was special.

Agree that the Dumezilianists have tried to overfit the tripartation framework. However, we can discern several instances of it Celtic, Italic, Greek and to a lesser degree in Germanic and Anatolian (perhaps preservation bias), favoring its presence in PIE. As you are aware, tripartite castes are seen in old Germanic tradition. These are linked to the emergence from the primordial being – mirroring the puruSha. Hence, we may say that elements of this were there in early IE even if much better expressed in I-Ir.