Further Bcash technology (BCH and SV) is inferior, because its security model is weak.
Incorrect. It is
SegWit that has an inferior security model.
Its security model is weak for a number of reasons, all of which come back to a lack of effective decentralization.
I might agree that BCH and SV's
currently actualized security is below that of BTC. As it is secured with less hash power. Which, to the extent that such might be the definition of 'decentralization' you are employing, comports with your statement. But that is not the same as a deficient security
model.