In an ideal world, you might be correct to say there should be no incompatibility issues between Numbers for iOS and Numbers for Mac. In that same world, you might be correct to say there should be no difference in capabilities between a Honda Ruckus (a gasoline powered scooter with a 50 cc one cylinder engine) and a Honda Accord (also gasoline powered, with a 3.5 L V6 engine). Both, after after all, are designed to transport people and goods from one place to another, and both are Hondas, just as both versions of Numbers are designed to hold and manipulate numerical and text data, and both come from Apple.
In the real world, of course, differences and incompatibilities do occur.
Since your main purpose seems to require using the iOS device in the field, I would suggest you develop the Numbers document on that machine, then tackle the issue of transferring the gathered information to your Mac.
An alternative might be to wait for the rumored upcoming release to the Microsoft Office apps for iOS, and see if MS has achieved a higher degree of compatibility between the platforms.
You might also check the iWork for iOS community, where you'll find a greater number of people who use both the iOS and Mac versions of the iWork applications, and have had a better opportunity to come to terms with the issues you identify.