Things get a bit sub-optimal when you end up with a mix of roleplayers and metagamers at the same table and people end up frustrated. So you've either got to decide how to point the horse to one direction or the other, or find compromises that keep everyone entertained.
However, hex-map and all, this remains a roleplaying game and not a tabletop wargame, which brings me to the next point. Certainly it is easier (and probably more fulfilling) to apply things like Tactics in the sense we're discussing it in theatre of the mind. No argument there. But the existence of a hex-map does not invalidate other ways. Here's a whole bunch of thoughts on that:
- ten meters is a pretty big amount of space. Within any given ten meters there are countless furrows, brush, tall grass. There's nothing stopping you from presenting a map to the characters and then permitting pieces of cover or concealed approaches that were not there initially to be discovered (ie, added) through play.
- in my most recent session I allowed a character to use their recon skill similar to a mobility roll, to move up undetected through a wheat field. With each success granting them a hex closer to the enemy that they were confident they could move without being seen or heard. This worked pretty well. It's easy to see other applications of this sort of thing.
- "you see a hill that dominates the approach to the bridge" is a good example. There are many others. As characters enter a map, if there are any who have decent Command or Recon skills, they should get knowledge like that, or "that building looks like a likely sniper position." No roll required for that. However, a roll to set up a concealed LP/OP on the hill overwatching the bridge might be -- to later determine the likelihood of patrols coming across it, etc. The flip side of letting players solve problems with intelligence is of course that many of them may be playing characters with more training knowledge than they themselves have. I have a player like this. His character gets fed this sort of knowledge to allow him to appropriately solve problems he otherwise might miss. Of course this depends on your group, as does everything.
- the terrain may be the battlefield but it is not the whole story. METT-TC always applies. So even if the terrain remains 100% unchanging, plentiful other factors like time of day, weather, observed patrol patterns and behavior of the enemy, etc etc will always apply. Someone who is a good commander will be able to see all of those factors to their advantage and make the most of available recon/knowledge -- while someone who is not, will not. This offers endless strings the GM can pull: enemy morale, how many reserves are available and when and where they show up, how well armed they are when they do show up, etc. Each of these things can be easily tweaked to reward or punish characters appropriately.
Because this is not a tabletop wargame, there is no such thing as hard truth. There is no such thing as "fair." (and if there was, the PCs would have very short, unsatisfying stories!) There is only the perceived reality that unfolds over time. The only thing "concrete" in a roleplaying game is the past -- and sometimes not even that. The rest is, at best, concrete that hasn't set yet.
This is not cheating or pulling punches. It's using all the tools in the toolbox to make good stories that everyone feels like they had a hand in. Basically everything in a roleplaying group is a Skinner box, and everyone -- but especially the GM -- has a powerful hand in shaping that behavior so it is the most fun for the particular people involved.