. Maybe more hills are the answer
I was thinking we need more terrain on the table. So roughly how many pieces of terrain is 1/3 of the table?
That will depend on the pieces, and how you play them.......
Each piece has a "footprint" which will in most cases be slightly larger then the actual size of the feature. Each piece also has a function or combination of functions, and you will want to take those into consideration too (I guess I realy should finish the article I started on this before Steve was taken from us). In short;
Make sure that you have several largish pieces that block LOS (here we generaly play that LOS in a built up area (a determined area with one or more "man" made structures also counts as blocking LOS but LOS out of, into and inside it is set to 4cm (compared to the 2 in woods etc)
Make sure you have a good mix of movement blocking and/or movement directing pieces. These can be a LOT of smaller lineair ones in any combination with bigger things like (cliffed) hills etc. Note that a "village" (built up area) blocks movement too for some tropptypes ! so with bigger built-up areas, consider running a road through them to allow eg. cavalry to move though them in line ........
Assuming you play on a 120x180 table, your terrain should cover a 120x60 area.
Hills, water features, swamp etc have their base size as-is
Woods and built-up areas have a footprint that should allow for 8-10 cm surrounding the actual piece
Lineair obstacles have a footprint that is rougly 3x their base width (so a 12cm section of wall on a 2cm base would have a basesize that is roughly 6x12
Does this help ?