First time buying brushes and don't know if I purchased the correct ones

[Cathy Austin]

I'm just buying my oil brushes and wanted to see why I need a 12" flat & filbert  when I am only painting

16 x 20 landscapes?  Seems like all I would need is one really large brush to start?  I am getting #2, #6

but what else is needed for my first set.  I have been studying on my own.

 

Shouldn't I have a sable fine brush for fine lines?

 

Thank you for your help!

Cathy