Why not make ECM jamming only turn off all ewar mods on the target ship for the duration of the jam cycle?
Optionally include any/all of: scrams, webs, disruptors.
If it didn't apply to points or webs then ECM would be used to 'neut' opposing ewar. But becomes useless if none is fielded. Ironically, just like an ECCM module.
Though this still doesn't fix the random nature of ECM mechanics..