can a mech mount two ECM modules? Could it be two Guardians or should it be a Guardian and a Angel? For instance can a Guardian be set in Ghost Target mode while a Angel be in ECM/ECCM mode?
Techmanual, p213:
"Units with multiple ECM suites may use only one at a time in game play."
And it repeats that line for stealth armor.
So, yes, you can have multiple, but no, you can't have multiple on at the same time.