The (C12-001 004 N) ECU with the larger rectangular multi-legged components is newer than the other one you have pictured. I wonder if it's aftermarket or a newer factory replacement. If it were me, I'd use the newest one you got that runs properly. The pics aren't clear enough for me to pick up any date codes, but it's likely that you could be able to closely estimate the dates of production by determining the manufacturing date of some of the parts used on the boards. Also, it's academic, but... The components loaded into that white holder are not resistors They're actually inductors. They use a L-C (inductor and capacitor) as a filter to try to prevent high frequency interference from entering the ECU circuitry. Each pair of little L's and C's is a filter on a pin that enters the case. I bet they decided that some of them were no longer necessary as time went on. Better filtering elsewhere in the car maybe? I wouldn't call the more heavily loaded filter section "overkill". Noise is a tough and difficult to pin down opponent. And sometimes when the schedule is looming there comes a time where sprinkling some insurance in the form of some cheap components is the right course of action.