How to synchronize a large number of fast, high power IR LEDs?

I have a board with four parallel strings of three IR LEDs (OSRAM SFH 4232), triggered at 1MHz for up to 33% duty cycle.
A trigger comes into the board and goes
1. to a transceiver (SN74AVC1T45) that level shifts to 3.3V, then
2. to a quad XOR (74LVC86A) that splits the signal, then
3. to four low side gate drivers (UCC27524) that switches the four strings of LEDs, with series current limiting resistors, directly.
That keeps the four strings matched to less than 3ns while only imparting about 15ns propagation delay.

I need to scale this up to 225 LEDs (45 parallel strings of five) while keeping them matched to <5ns with a total propagation delay of <30ns.
How can I keep such tight timing?