With a program like Keyclone (www.solidice.com/keyclone), you broadcast keys.
This means you can press 1, on any window and have 1 pressed on all of the others as well.

On your paladin tank, the macro bound to keystroke 1 might be.
/castrandom Holy Shield, Consecrate

On your dps shaman, it could be.
/castsequence [target=focustarget] Flame Shock, Lava Burst, Lighting Bolt, Lightning Bolt, Lighting Bolt

On your healer/dps shaman it could be
/castsequence [target=focustarget] Flame Shock, Lava Burst,,,
/castsequence [target=tank's name] ,,,Healing Wave,

It all depends on how you have your macro's set up.