Glencore buys Bowen CC neighouring mine, page-10

I've got a somewhat different perspective, but don't disagree that strategic assets can sometimes add substantial value.

IMO there is limited value in "strategic" if you are only likely to be able to sell the asset to one nearby player, and if the one player has large and long term reserves - they will just wait you out until you relinquish your tenement.

You need to select and hold an asset that (a) has multiple options for add on to existing or likely future adjacent players AND (b) potentially has stand alone development potential if coal prices support it. Otherwise you are simply land banking and spending money on boreholes.