I think it would be very beneficial to have every tile account for 100% of it's cultural makeup (just like cities). As of now, only the civ with the strongest cultural presence is displayed with its percentage.

When I mouseover a tile, I want to see more than "14% German." In this case Germany has the highest percentage, but who else has influence on the tile?

The current system leads to too many cultural surprises and interferes with strategy IMHO. I need to know if the leading civ is removed, who gets control of the tile after that. This isn't even possible with cities until spies come along.