Most people here also didn't get any partial panel instrument training either. I'm not sure I agree about southern only heading. Lead/lag errors are the only issues that apply to the compass when associated with non-east/west headings. If turning towarda northern heading you'd overshoot the compass heading and undershoot the rollout to a southern heading. Either way it won't be accurate in the short term. Are you thinking just due to the physics of a compass that it's more likely to be stable and leas prone to swinging if the magnetic pull is behind the gauge? I don't think that would make a difference. It's been a while since my most active CFII days, so I could be missing something...

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