What is this freak talking about:
Not to be confused with dyslexia (mixing up letters, poor grammar and spelling). Dyscalculia means you are shit at numbers and everything pertaining to mathematical concepts. Even telling left from right is difficult. Estimating the count of objects (talking about 4 to 8 objects approx here) is impossible since you have to count them (hoping you don't lose track). Forget remembering phone numbers, or any other arbitrary number combination. Forget confidently doing any calculations that requires more advanced crap than adding two numbers together on a calculator. (You'll need the calculator cause you can't do simplest calculations in your mind.) Forget memorizing sequences, etc.
Now the question again: How competent can such a person expect to become at a very number-heavy game like WoT? Any ideas which tanks in particular or which classes or tiers might be suitable for them?