Driving series parallel combination of LEDs with a constant current source
Datasheet says:

Samsung maintains measurement tolerance of: forward voltage = ±0.1V

These LEDs are sorted (binned) by Vf by the manufacturer (also color temperature, tint, efficiency, etc). So if you order a reel of them, all the LEDs will be well enough matched that you can get away with wiring them in series parallel strings without resistors.

Of course Vf depends on temperature, so the heat sink should be designed to keep them more or less at the same temperature, or the series strings should span the thermal gradient so they each include the same number of hot and cold LEDs, for example.
If you want to calculate some probabilities, let's assume the voltages are uniformly distributed in [0,1] interval for normalization, and plot the probability density function of the sum of 10 samples:

If you use long LED strings, the law of large numbers is on your side.
Note the pdf of the sum of two variables is the convolution of both pdf's, so just run:
from numpy import *
p = ones(11)
q=convolve(p,p) # 9 times
plt.plot(q); plt.show()