The controls cannot be remapped.
The idea is to use the arrow block (reverse T) for motion, and Right Ctrl (with your thumb) and NumPad 0 (with your pinky) to switch Vikings.
Of course, I only realized it in hindsight, since I got into the habit of playing with the numerical keypad. So I was using the NumPad 0 with my thumb, and Left Ctrl with my left hand.
Little did I know, that for people like me, they also mapped the Viking switch keys to Pad7/Pad9.
The thing that I _did_ do correctly was using ESDF for the action, instead of relying on Spacebar. ESDF was remarkably intuitive and I have since adopted it to use in some other games.
