So it seems to me that the next big decision to make is how to use our air force:
Option 1: Hold back and only deploy the air force around the cites
Advantage: Preserves the air force. Achieves local air superiority around the cites which are the main points of battle. Air force will be supported by the city anti air defenses.
Disadvantage: Landing of enemy troops by landers is uncontested, allowing faster deployment of Ork forces. Movement of enemy troops to concentrate attacks on specific targets is uncontested. Retreat of enemy forces back to space is uncontested, allowing faster retreat of the Orks once our reinforcements show up (note that they will have 2 weeks warning).
Option 2: Hold back and only deploy the air force to attack targets of opportunity, and around the cites
Advantage: Preserves the air force. Achieves local air superiority around the cites which are the main points of battle. Air force will be often supported by the city anti air defenses. Movement of enemy troops to concentrate attacks on specific targets is contestable. Probably provides best kill ratios, and allows focusing the air force on important battles.
Disadvantage: Landing of enemy troops by landers is uncontested, allowing faster deployment of Ork forces. Retreat of enemy forces back to space is uncontested, allowing faster retreat of the Orks once our reinforcements show up (note that they will have 2 weeks warning). Possibility of air force deployments being cut off and destroyed, (ie we get baited into a trap).
Option 3: Hold back and only deploy the air force to attack targets of opportunity, and around the cites. Launch massive attack on the landers when the Orks try to retreat.
Advantage: Achieves local air superiority around the cites which are the main points of battle. Air force will be often supported by the city anti air defenses. Movement of enemy troops to concentrate attacks on specific targets is contestable. Probably provides best kill ratios, and allows focusing the air force on important battles. Attempts to kill the Orks when they are retreating, making retreat difficult.
Disadvantage: Landing of enemy troops by landers is uncontested, allowing faster deployment of Ork forces. Possibility of air force deployments being cut off and destroyed, (ie we get baited into a trap).
Option 4: Attack the enemy landers and landing zones during their initial landings.
Advantage: Reduces enemy lander capabilities, slowing their deployment and making teleportation via Roks more essential to that deployment, (limits the number of landing locations). Allows attack runs on the landing zones before Ork forces are deployed (meaning less AA defenses). Reduces enemy lander capabilities so that moving forces around is less possible. Reduces enemy lander capabilities so that retreat is slower and more difficult.
Disadvantage: Enemy fighters will contest this. Much higher casualties among our air force.
Option 5: Attack enemy fighters and landing zones during initial landings.
Advantage: Allows attack runs on the landing zones before Ork forces are deployed (meaning less AA defenses). Has possibility of achieving global air superiority by eliminating the enemy fighters, which would allow uncontested sorties by our air force afterwards. Including attacking enemy landers. Possibility of destroying enemy lander forces with the enemy force half deployed.
Disadvantage: Much higher casualties among our air force. Allows the landing of more Orks during initial landings.
Option 1 & 2 is basically what we did against the Necrons, and have done against most enemies due to being heavily out numbered in the air.
Option 3 is probably the minimum we need to do if we are to achieve the strategic goal of crippling Garkill and possibly killing him.
Option 4 is what we tried last time Garkill landed, and it was very costly to our air force, but probably did achieve the goal of forcing deployment via Roks instead of all over the place via landers.
Option 5 is the classic air superiority strategy, and if we can achieve the aim of eliminating Garkill's fighter cover would give us a huge advantage the rest of the war.