The Realms is massive and at different times, different politican issues have been there - so you can do almost anything in it. However, I find it too much. Smaller worlds suit me better, so most of my settings have three or four heavily populated areas (the size of a FR Kingdom) and then a lot of ruined spaces with sprce populations.
The best way to deal with that if you want is to just focus on a region, like grab the Moonshae Isles book or the Border Kingdoms, and use those, most of the time you can just ignore what else is happening in the Forgotten Realms.