It sounds like what you are referring to as "compliance" is really an issue of airway obstruction from less-than-adequate positioning. Lung and chest-wall compliance should never be a problem, outside of a patient with lung disease or some sort of restrictive thoracic disease or severe truncal obesity.
The biggest problem that most people have with mask ventilation is not maintaining an open airway - that's what happens when your head positioning is not right, or, the "head is tilted down". It takes quite a bit of practice to simultaneously hold a good mask seal and a good head position, especially with one hand. In some patients it is really hard, even for people who do it every day.
If you have to choose one or the other (a good seal or good head position), always choose a good head position. This is because you can usually still generate some airway pressure with a small mask leak, and if the airway is open and you have high oxygen flows, you may get the benefit of some apneic oxygenation, even if you aren't ventilating that well. Most importantly, if the airway is not open, your good mask seal is meaningless.....you aren't going to get flow into the lungs, and you very well may end up with it going into the gut.
Basic airway adjuncts are very helpful, and I can't say this enough: LMA's are seriously under-appreciated in the prehospital setting.