I see many people use a canvas much smaller than Bob's 18x24. I'm wondering if you are still using his large brushes, or, is there something else you use?
When I do smaller 11x14 size I do not use my 2" brush. But I still use the 1" or oval, and the #6 fan as needed. I also have MANY small brushes I use for pet portraits, and I will use some of them on small landscapes.
Never did use a two inch myself, inch and half is more controllable IMO