If anyone’s interested but haven’t played it, the original ZT2 (not played ZT1 and this isn’t in the new XB1/PC ZT) has a similar terrain tool (though this has more options obviously).
I felt immediately comfortable with raising/lowering terrain with the brush sizes in Unity cause of that XD.
Can’t find any good videos on it but thought I’d mention it for anyone interested (or people who have played it and know what I mean 
)