I'd suggest CmdOps if you aren't totally wedded to turn-based and hexes. It is accessible, yet deep and complex, with an emphasis on soft factors (command, morale, fatigue, supply, terrain and manoeuvre) rather than exclusively on equipment and 'troop quality'... you can easily 'throw away' a heavy tank Bn with TigerII by running them out of fuel deep behind enemy lines, or by getting them embroiled in a knife fight, with enemy infantry and tanks.
Larger scenarios apart from having a longer duration, are similar in complexity to smaller ones ~ despite the much larger unit count, as units follow 'plans' made by the player or AI, rather than each being moved manually each turn. Tasks to perform within the game tend to be forward planning, "real-time" analysis of intel picture as it changes and actions/reactions in response to opportunity/threats ~ often a 'good' plan will need little direct manipulation, and the tension comes from watching for the unwelcome/unexpected ~ other times a wholescale cancellation and replanning of the effort is needed to respond to the AI's threatening posture, or a 'bonus' opportunity.
There is a demo, and lots of helpful people in the subforum to answer questions. The manual explains most things, and there was a strategy guide for earlier versions (AA:HTTR, rather than CmdOps:HTTR, but most is still valid).
It is closer to a 'real' command experience than most titles that have been available, and more accessible than the few that have tried to break the same ground ~ plus the AI is fairly competent.