It's pretty late in the game for an axe rush. Might work this game, but "it's 1800 BC and I'm feeling crowded, maybe time to start thinking about axe rushing" is not a habit I would recommend forming. Elepult warfare looks pretty attractive here though. You've got the Ivory, you're not far off from Construction on the tech tree, you'll have plenty of forests to chop, and your neighbors are at pretty much the ideal distance for an elepult breakout war - enough land available without war to get 3-4 good cities as a foundation, but not so far away that you'd spend forever just moving the units around. Might even be able to double up, take out two AIs in a row.