We need a protractor and ruler, or equivalent tools for the map, so that one can measure distances and angles to properly do land navigation. Especially critical on harder difficulties where the player's position is not shown on the map.
- Legacy ID
You have map grid and a compass.. it's all you need to navigate along with your eyes to find points of interest and / or reference points.
Map grid is 1Km per side for the "big squares" and 100mt for the smaller ones (when zoomed in).
Also A3 map shows some quite good satellite textures in the map screen that will help to find your way.
Use these along with map markers and you're good to go.
ACE mod will bring that feature in the future anyways.
(all of this was to say basically that devs won't probably add map tools in the release :P )
Except that the compass doesn't show up in the map screen, and you still have no good way to measure distance unless you hold a ruler up to your monitor. So better to put a ruler in the map screen, or fake it with a point to point tool of some sort. Grid squares do no good if you can't figure out how long a line from point a to point b is.