The BFG KM2 and the Nitto Terra and Trail Grapplers are all 3 ply sidewall...the additional ply rating goes for the tread side and are added together for total. 3 ply is some of the strongest and most resilient sidewalls out there by todays standards.
LT-metric, LT-Flotation and LT-numeric tires will be branded with their load range ("Load Range E" or "LRE") or their ply rating ("10 Ply Rated") on their sidewalls and list their appropriate load range letter in their descriptions as LT245/75R-16E, 7.50R-15D or 31x10.50R-15C.
I had all kinds of problems with sidewalls with older BFG AT radials in 80s and 90s....my Nitto Terra Grapplers were some of the toughest tires I ever owned in mud, sticks, staubs, oyster shells, boulders, concrete curbs, drain pipes, rail road ties, and loose shale that was sharp as a knife...and never got a cut on any of them....I never air down below 18 psi though either which makes a difference I think...though I never failed an attempt that like built vehicles were doing with lower pressure. Tread design, rubber compound AND psi all impact how they perform...and the Nittos are at the top of the heap I think. I also have had good luck recently with my KM2 on my FJ60....similar ability on trails and tough as nails as well...also never go below 18-20psi on these tires but I walked right up climbs, ledges and loose trails where others were spinning in more built vehicles...again tread design, rubber compound and pressure all contribute...just one of the three will not suffice.
so you will be hard pressed to find a radial offroad tire with better than 3 ply sidewall that is not so specialized you will not want to drive it on the road....3 ply is the standard for radials now. 10 ply, 12 ply...are combination of sidewall and tread ratings together....apples to oranges when you compare 3 ply sidewall rating to 10 ply TOTAL rating.
Firestone Destination II, Hankook Dynapro, Nitto Trail Grapplers, BFG KM2, Cepek Mud Country are all 3-4 ply sidewalls with 10 plywall total rating if not mistaken. More plys are equal to heavier tires all other things being equal...
There are tradeoffs....but all great tires and designs.