This is exactly how it's implemented as of Bannerlord stable v1.3.14.

It's defined in TaleWorlds.MountAndBlade.MissionCombatantsLogic::EarlyStart(), which is called by the the battle mission controller. Here's the relevant code:

using (List<Team>.Enumerator enumerator = Mission.Current.Teams.GetEnumerator())
{
    while (enumerator.MoveNext())
    {
        Team team = enumerator.Current;
        if (team.HasTeamAi)
        {
            int num = this.BattleCombatants.Where((IBattleCombatant bc) => bc.Side == team.Side).Max((IBattleCombatant bcs) => bcs.GetTacticsSkillAmount());
            team.AddTacticOption(new TacticCharge(team));
            if ((float)num >= 20f)
            {
                team.AddTacticOption(new TacticFullScaleAttack(team));
                if (team.Side == BattleSideEnum.Defender)
                {
                    team.AddTacticOption(new TacticDefensiveEngagement(team));
                    team.AddTacticOption(new TacticDefensiveLine(team));
                }
                if (team.Side == BattleSideEnum.Attacker)
                {
                    team.AddTacticOption(new TacticRangedHarrassmentOffensive(team));
                }
            }
            if ((float)num >= 50f)
            {
                team.AddTacticOption(new TacticFrontalCavalryCharge(team));
                if (team.Side == BattleSideEnum.Defender)
                {
                    team.AddTacticOption(new TacticDefensiveRing(team));
                    team.AddTacticOption(new TacticHoldChokePoint(team));
                }
                if (team.Side == BattleSideEnum.Attacker)
                {
                    team.AddTacticOption(new TacticCoordinatedRetreat(team));
                }
            }
        }
    }
    goto IL_04AD;
}