Hello! I have a 12ga Tracker II. I have a hard time with the "finer" open sights that you may find on some slug guns or rifles, but I have done very well so far with this one. The rear sight is a sqare bottom notch, the front sight is square topped. When the front sight is in the notch, centered and level with the top of the rear sight, you're on!
Now, as to your concern about the front sight on other guns being too high, I would much rather find the front sight too high [Point of Impact (POI) too low] than not high enough. Because of the the style of the front sight, I had no trouble or qualms taking a file to it.....
What I did first though, was find a slug load that I liked, in regards to price, group at 50 and 100 yds, and recoil. This I did, and the rear sight had to be elevated to max to be on target. BUT, I was able to do this all BEFORE I did any permanent filing.
Then, to get the rear sight down near the middle height of its adjustment, I lowered the rear sight to what I thought would give a reasonable adjustment range, and began filing a little on the front sight until I pretty much had POI where I want it. I have since bought 2 cases of that slug, which will last me quite some time, when you consider that now I only need to shoot 2 boxes [10 rounds] total at the range plus the one needed to bring down a deer, each season.