In two-player Agricola, the first Take Stone action space appears in Rounds 5-7. Apart from one or two Minor Improvements, there is no way to get stone earlier than this. Having played quite a few such games, I feel that this is an unfortunate limitation, as certain cards such as the Axe and the Peat Charcoal Kiln (in Farmers of the Moor) are very useful if played early. But as they cost stone, you might have to wait until round 7 to have a chance, and this almost completely negates their usefulness.
Games with 3-5 players have ways of picking up small amounts of stone before the Take Stone cards appear. I feel like an equivalent would make the two-player game more flexible. Would it break the game to modify the rules slightly (e.g. including the "Take one building resource" 3-player action card, or something else along those lines), or should I just accept the limitations? In most respects the game seems very well balanced but I feel like this is an exception.