Mils/meters is very easy to use once you’ve done it for a little bit.
If you can work in yards you can work in meters.
Average dude=just under 6’, or about 1.8 meters
Average dude from hip to head= just about 3’, or 1 meter
Average shoulder width=about 19", or 1/2 meter (50 cm)
Average rifle length= just under 3’, or about .9 meters (90cm)
Average 3rd world vehicle tire height= 14"-16", just under 1/2 meter (40cm)
As a team, most things can be solved by just talking in Mils for corrections, or in meters/fractions of meters, which are close enough to yards when talking about short distances like those used in corrections. Really though, communicating in mil-hold or adjustment is preferred over arbitrary numbers of estimated length when relaying hold/adjustment. If the spotter gives “1/2 mil low”, it puts both the spotter and the shooter on the same page as opposed to “hold 18” high", as that then forces the shooter to guess at what 18" looks like at the estimated range, which can be difficult if there isn’t any kind of known length indicator right beside the target, which can make follow-on corrections really weird.
By yourself, it’s really easy/fast to track observed strike in mils and correct with a mil based adjustment. Juggling MOA adjustments with a Mil reticle is a pain. 3.44 based math just doesn’t work as fast in my head as 10 does, and can get confusing when talking corrections or doing rapid math.
None of those concerns are really present in benchrest/F-class (or whatever) competitions, so there is no detriment by using a simple reticle with whatever adjustments are fine enough to get precise POA/POI at range.
FWIW, the most successful military sniper teams work in mils/meters.
It isn’t because there is a conspiracy to convert us to the metric system, it’s because it works.
