Worth trying your original coilpack on your other halfs car to see if it runs OK.
Coilpacks are only double sided coils ie two coils in one each feeding a pair of cylinders, so hard to see how it can feed one and not the other one on it's pair, unless as suggested there is a connection problem INSIDE COILPACK, very unlikely as a known good one does the same.
It sounds as though your car has developed a fault like lack of compression due to sticky valve follower ?
The connections from loom to coil must be ok otherwise you would lose two cylinders if eithe one half stopped working ok.
You coulkd do worse than try both on other halfs car to see if they go OK on it, you say it does not fire on the car but have you put a plug in the end of pulled off lead to check it is firing ?, whilst engine is running on three ?
tabetha