Coming to gaNapati/skanda -
rudra himself is a man-killer and cattle-killer.
But he’s also the medicine bringer and can heal once pacified.
His sons - the marut stormtroopers is the basis for later day evolution of skanda and vinayaka.
Both of them are trouble makers - can bring obstacles or pediatric diseases.
But once pacified, are graceful to the devotee.
“maruto gaNAnAM adhipatayaH te mA avantu”.
Already maruts are “lords of the troops”.
GaNapati is just “lord of the troop”.
“deva-senAnAm abhibhanjatInAM”.. mantra to maruts reinforces the sena/army connection.
Skanda literally is devasenApati.
The vaishNava ectype of the “lord of troops who’s obstacle remover” is vishvaksena
and accompanied by jayatsena (imo skanda equivalent).
His retinue include horse-headed and elephant-headed deities.
Both skanda and ganapati can be explained as internal evolution of our deities
without positing some hypothetical tribe with a hypothetical elephant headed God.
To conceptualize a deva with elephant head you just need to be exposed to an elephant.+++(5)+++
That’s the parsimonious explanation.
To sum up- Even is a deity’s form is temporally later,
or even if it’s inspired by a foreign religion,
an H “doesn’t [necessarily] adopt” the foreign god but sees the form as a new manifestation of deities he always worshipped. /fin