Everyone involved is a refuge3e from the '90s, and know the basics. It's just the tactics that tend to be deficient. I tend to be too aggressive, one guy tries to make BA act like hunchbacks, and so on.
I advise "Combat Simulator" scenarios, followed by after action sessions. My group is made up of war gamers, so most have a grasp of tactics that they apply in BT.
A Combat Sim scenario uses the players' unit against random foes. Players are given a briefing on what to expect and their mission goals and the scenario starts. Campaign-wise, it is playing out simulator sessions, where nobody gets hurt and no losses incurred. The idea is to train your players in the tactics of the game to make them better players.
When I run a Combat Sim scenario, I keep an eye on the players' actions and as GM, I will freeze the action is a player makes an obvious blunder in order to ask them, "Why did you choose that maneuver?" If they don't want the opponent to know, I take them aside. Normally, a bonehead move results in a bonehead answer, so I "save" the game at that point (take a photo of the map and fig positions) and allow the play to continue. If the blunder fails, we "reset" the game at the "save" point and allow the players to try something different, or, the GM will suggest an alternative plan.
A basic scenario is to allow each player to know the capabilities and weaknesses of their personal mechs; Each mech has 3 to 4 properties: Speed, weapons, armor and other (Other is special equipment/abilities, such as targeting systems, ECM or Active Probes)
Light mechs tend to prioritize Speed, Weapons then Armor, while Assault mechs prioritize Armor, Weapons then Speed.
Players should know when to maneuver to prevent being hit and when to stand and slug it out.
Every player should know the "sweet spot" of their weapons, the optimal range to get the best odds of hitting...and how to avoid the "sweet spot" of their opponents' weapons.
Each training scenario should be tailored with the players' deficiencies in mind. If players have trouble coordinating, make a scenario that requires team work; If players don't know how to use indirect fire, have them concentrate on that. The idea is training and learning to apply that training in real battles.
One deficiency a couple of my players had was mine fields. The first encountered mine fields and neglected to inform the players moving up behind him, so they hit the mine fields too. Communication and coordination are key on any battlefield. Each mech and vehicle has a map on their tactical display and the payer could have sent the data to everyone on the comm net. A mine marker would be placed on the map and problem solved.
The second player drove his vehicles through a mine field and crippled a couple of them. His response was to reverse gears and back over the same mine field, taking further losses. After I peeled my palm from my face, I froze the scenario and asked all the players what the SOP (Standard Operating Procedure) for mine fields was.
Mine field SOP:
1) Report (Mark on the Map)
2) Mission options: a) detour around it. b) clear it.
3) Be aware of more mine fields
A mine field serves these purposes:
1) Slow advance
2) Channel movement (detour)
3) Cause damage/losses
Minefield rules are detailed in Tactical Operations. If intend to use them, get to know them well.
The above are only examples and suggestions, of course, so use them as you wish. The purpose of training scenarios is to eliminate "trial and error" gaming, where the players expend time and energy reinventing the wheel, instead of enjoying the game.
What I consider of vital importance is the post-game after-action session. Usually, we would go to a favorite diner and discuss the scenario in detail, with the goal of everyone gaining useful experience.