I'd like to voice an opinion. I've used the click-and-drag with my groups in almost every one of my online games. The incredible convenience of this was that I could arrange and sort my front infantry line and drag it into a proper line without gaps. This way, I could put a power infantry unit in the center and place anti-cavalry or spears on the wings. The problem with RTW is that if I want to have a line with multiple infantry types, I'm forced to use the "single line" command, which sorts the infantry out for me. Reorganizing my army into something I did not order is not conducive to victory.

This "single line" group formation is no cure for the lack of a click-and-drag for groups. The click-and-drag was much better for forming and reorganizing.