Aupmanyav ... don't know where you are coming from, in regards to Buddhism, so don't feel disturbed what I might say about it now or later ;-) Namaste.
So my educated guess, is that Buddha was not just being "skillful" when preaching in Hindu terminology.
How do you like The Hindus by Wendy Doniger?
Don’t worry, Baruch. What you say about Buddha is not going to disturb me. I have two Gurus and Buddha is one of them (the other is Sankara of Advaita, non-duality). I am a Kashmiri.
I think Buddha was quite skillful. He retained ‘karma’ for the benefit of society. We have a saying in Hindi, from Rama Charit Manas of Goswami Tulsi Das, which goes like this:
‘Bhaya bin hot na preet, Gopala’ (O Gopala (Krishna), love does not develop without fear).
We love our parents, social laws, wife, so as not to loose their love. If there is no benefit, you may not find people engaging in good deeds. So, Buddha retained the carrot and sword policy (which you find in all religions as also in society) without subscribing to Gods or soul. I think he used minimal hocus-pocus, but only that which was necessary.
I have not read Wendy Doniger except for a few excerpts long ago, some I agree with some I do not agree with. I think Wendy, apart from the atrocious last books or articles, has written something sane about Hinduism too. You see, one could spend time doing better things than read what people say Wendy has written. I have my views no Wendy can change that.
As for Hinduism, it was always developed to the best of its times. It has a dynamic format, something like Wikipedia. It is still the most developed with Advaita.