‘ And they gave him seventy pieces of silver out of the house of Baalberith, with which Abimelech hired vain and light persons who followed him.'
The house of Baal-berith may well be the Temple fortress of which the remains have been discovered. This would have a treasure house of gifts given to the Temple and to the god. The ‘seventy' pieces of silver probably denote a divinely perfect amount (seven intensified), to deal with the seventy sons. Thus he hired ruffians for his purpose. These may well have been Habiru mercenaries.
It is nowhere suggested that the people of Shechem were Canaanites, although like all in the land they were mixed up with Canaanite religion. They appear to have been a mixed population including many ex-Habiru. While they may genuinely have intended to equate Baal-berith with Yahweh and be faithful to His covenant, it was asking too much of them when even true Israelites engaged in such syncretism.