This is complete nonsense. I can say first hand that influence followers can be an extremely powerful weapon (and occasional regional maintenance tool) when used correctly. It's really good at lowering enemy realm control, for example. And if you can't find something useful to do with that then the problem is with you rather than the mechanic not doing anything.
That being said, reducing the number of followers lost by using it wouldn't hurt.
My experience is always the same with these abilities. Zero impact, huge cost. Every time. Different characters (all top skills in oratory), different continents, targets in different starting condition, always the same result. Always. I used to think it was powerful and feared enemy priests, but that's before I became experienced at playing a priest myself.
