There is no way to change the tactical map hotkey normally, you have to use seperate programs to do this. If you have a keyboard that comes with software that you can rebind keys, you can make tab = numpad 0.
If you don't have keyboard software to do this, you have to do it with AHK.
Here is a script to make tab = numpad 0.
Script:
#IfWinActive, Company Of Heroes 2
Tab::Numpad0
[:

uspend
Return
----------------
Edit: There is an emote in the script...... its supposed to be [:: Suspend
But make sure to put no space between the : and the S, I just did that to not make the emote.
AHK is safe to use in coh2 also.
Hope this helps!