Well, in the defense of the "Asian" POV, Indy... A 6-foot tall, size 10 combat boot-wearing GI wasn't the norm back in WW2... The average height for US Soldiers was about 5'9"... According to what I've read, it was due to the Depression and a decided lack of a proper diet that kids didn't grow as tall as they have in subsequent generations... WW2 GIs that were nicked "Stretch" or "Bull" were likely guys that were 6'-6'1 and in the 190 lbs. range... Pretty average for today. Tamiya figures scale out, generally, to 70 inches tall, or 5'10"..
The best way to make scales match up in mixing figures is use a weapon for scale.. That's where manufacturers have to be watched, IMHO... If the M1 or KAR-98 scale out properly, use that as a "ruler"... Also, don't mix weapons from manufacturers... If you're using say, Dragon's weapons & figures, but mix Dragon, Tamiya, and ICS figures, use ONLY the Dragon weapons...
Also, it's easy enough to "stretch" a figure if modifying them is your bag... You can add a bit more putty-leg or torso-plug here & there...
The WORST culprits for figures in the 1/48th range are definately Tamiya's though... They don't even match the scale of their 1/48th aircraft figures... They scale out to about 5'3" tall in both the German and US Infantry sets...