Driving multiple MOSFETs with a TC4420
So current is charge/time, and you need to transfer 35nC in whatever the switching time is.  Now picking 1/10 the the period probably isn't good enough, because you want the interval during which the switching takes place to be short because this is the time when the current flowing through your device and voltage across the device are both large, hence power dissipation.  From the looks of your data sheet you might want to shoot for a switching time of about 100 ns, so then your gate current will want to be about 35/100 or about .35 amps.  You could probably do it with one of your TC4420 drivers since its peak current rating is up there around 7 amps I believe.  I think you should put separate series resistors in each gate line, perhaps 2 ohms, to equalize the currents.