Why you'd choose to use the arrow keys in any game for movement doesn't make logical sense to me aside from the fact that they're easy to differentiate. Right-handed people would have a severe advantage over a left-handed person using the arrow keys since we (the right-handed people) have numerous other keys within easy reach of each finger; Q, E, R, T, Z, X, C, V, space, etc - which we can bind to do other things. If a left-handed person used the arrow keys your options are severely limited.
Instead of using arrow keys, look at the keyboard. See how there's a pattern on the sides? The WASD keys are surrounded by many keys. Now shift to the right side of the keyboard. See how P, L, ;, and ' are surrounded by keys in a similar pattern? Use those. Your thumb can rest on the space bar as it does for a right-handed player, and if you use ALT to crouch in some games (like I do since I use a Razer Blackwidow) you can rest your thumb right between ALT and the space bar.
If you don't want to use those keys as movement keys because you've been using arrow keys for years and blah blah blah, then just remember you're still going to be at a disadvantage doing the same thing in games where PvP is a real thing since most other players can have many things bound within very easy reach....you can't.
