Funny, that does not look like a tonne & a half.
You've been diddled David!
Nice bit of scenery.
Given your proven ability to rip up place mats, may I suggest you
look to fibre-board &/or cork tiles for your hills?
It would give you a mixture of rough rocky out-crops & flat grassy bits.
Combine function (places to stand figures, the grassy bits) and looking nice
(the rocky out-crops). You could even make some small bases with trees &
bushes on, to place on the flat bits, e.g. 'before the ambush' setting.