Why `bien'? In English "my father knows plants" seems stronger than "my father is acquainted with plants". Doesn't bien mean well in this context?

When I hover over "acquainted" it comes back with "acquainted" again and won't give me the French.

Bonjour camarades, je pense que 'Mon père est familier avec les plantes' devrait être accepté. Je l'ai rapporté. Qu'en pensez-vous?

Also wondering about the distinction between "connaît" and "connaît bien".

yeah i don't quite understand why 'connait bien' and not just connait. in any case i put down 'mon pere est familier avec les plantes' which IMO is close enough and in English could certainly be used interchangeably.