Maybe try a 2 rank deep checker-board OOB...gives phalanx in both lines some maneuverability options, whilst allowing flanks to be protected and a battle line could be formed relatively quickly if necessary. Used the skirmishers to plug the gaps in the front rank to keep up fire as the enemy close.
I'd probably keep my elephant contingent away/separate from the cavalry, as they're more useful against infantry aren't they? Either send them up the middle to soften their line before the phalanx go in...you never know, they might not stampede back the way they came....or have them on the inner edges of the flanks and diagonally converge them into the enemy line at your chosen target point. Either way, they've got to 'deal with them' while your line goes in hopefully unmolested
