This is a Bard subclass that entirely focused on allowing allies additional opportunities to defeat their opponents. When you create your bard during any of the campaigns in this setting, you already must specify your subclass anyways, for convenience you already are allowed to benefit from the Tactician's Intellect feature before level 3.
Tactician’s Intellect
As part of joining this college, you are trained in the ways of strategic combat and advanced strategies. You gain proficiency with Cartographer's Tools. You can use a compass as your spell-casting focus.
Additionally, any bard feature that you have that is using your Charisma modifier can instead use your Intelligence modifier. For example, your spellcasting feature can now be based on Intelligence instead of Charisma.
Level 3: Tactical Mind
At third level, you can replace your Charisma modifier with your Intelligence modifier in Charisma (Deception, Intimidation, Performance, Persuasion) skill checks.
Additionally, you can replace one of your instrument proficiencies with a tool proficiency.
Level 3: Pieces on the Board
Your battlefield awareness grants you an additional use for your Bardic Inspiration feature, which is a collection of Strategies. These allow your allies more advantageous positions.
You learn the following strategies:
Follow-Up: When you can see another creature within 30 feet succeed on an attack that required an attack roll, as a reaction you can grant them a Bardic Inspiration dice. They can then immediately expend that die to make a follow-up attack with a weapon attack or a cantrip that requires a single attack roll, They can add the outcome of the bardic inspiration die to their attack roll. All attacks made as part of this reaction must target the same target/creature.
You can choose to use a cantrip like Eldritch Blast that has separate attack rolls, but then you only do one single attack roll.
Spread Out: As an bonus action, you can expend a use of your Bardic Inspiration to direct allies within 30ft, they can immediately use its reaction to move up to its speed, without provoking opportunity attacks. The number of allies that can benefit of this feature is equivalent to your Proficiency Bonus.
Defensive Stance: As a reaction to an ally within 30ft being attacked, you can expend a Bardic Inspiration and add the roll on that to their AC. If the attack still hits, they receive the Bardic Inspiration dice as if granted normally on a bonus action.
Level 6: Seize Initiative
At 6th level, you understand the flow of combat and can anticipate when dangerous situations occur. When you roll for initiative you can expend a use of your Bardic Inspiration, you and one target of your choice may add the result to initiative rolls. On your first turn in combat, you and your target have advantage on the first attack roll.
Level 14: Empowered Battle Strategies
Starting at 14th level, your existing Battle Strategies improve.
Follow-Up: If the follow-up attack would miss, they may keep the bardic inspiration dice.
Spread Out: You can now also use this feature as a reaction after another creature has attacked.
Defensive Stance: When you roll the Bardic Inspiration dice, roll it twice and use the higher outcome.