For the resistors inputs to the 'HC14s that are pulled high, I'd use a resistor pack for that - makes the track laying a lot easier.

You've also got 3 enable inputs - any particular reason for having them individually enabled? I'd be tempted to have a single enable pin (which means you could have fewer 'HC14s - although unfortunately, you'd still need 3).

You could also not pair them up - the DIR would be the other way around (and CLOCK would be inverted), but the DIR can be corrected at the other end (i.e. how you wire the motors) - and the CLOCK probably wouldn't hurt. In fact, EMC2 allows you to invert the DIR should you need to (and I'd imagine Mach3 would too).