The 'Missing Units'
One problem with Crimson Fields is the 'missing' units = and I don't just mean all the trucks, tractors and other 'soft skinned' vehicles needed to haul all the guns, ammunition, fuel, spare parts and other supplies for any mechanised force !
I would argue that, no matter how 'alien' the race, they must have encountered the same sort of 'combat challenges' that have faced human armies throughout our history. Whilst they may not develop the same solution, some solution will be found = and that typically means some specific type of combat Unit will be designed (or at least assigned) to address each challenge. Further, some things just naturally 'follow on' from others = for example, if you have tanks (or aircraft), the enemy will develop anti-tank guns (and anti-aircraft guns). Whilst development might be a little 'slow' - or 'politics' might demand that tanks be 'countered' by other tanks (rather than much cheaper anti-tank guns), we know the CF 'aliens' are capable of logical thinking because CF does indeed have AA Tanks and AA Guns - and even 'Interceptor' aircraft that have been specifically designed to combat the other aircraft types !.
So, now we come to the "elephant in the room". Assuming any sort of 'normal development' and 'logical reasoning' on the part of our CF 'aliens', we have to ask, where are the missiles ?
Missiles
As soon as some sort of primitive explosive is invented, 'firework rockets' become possible. Indeed, on Earth, the ancient Chinese employed 'war rockets' around 800 years ago (in 1232) about 400 years before the first steam engine (1606) not to mention 600 years before the first internal combustion engine (1872) and 700 years before the first heavier than air flight (1903)
So it is totally inconceivable that any 'alien' race, no matter how 'weird', would fail to develop rockets before self-propelled artillery, rail guns and jet aircraft !!
If they have tanks and aircraft, then they have the technology to build rockets, torpedoes and missiles - and if aircraft can 'fly', so can missiles. Even in the worst possible atmospheric conditions of hurricane force winds and lightening storms (generating massive EMI = electro-magnetic interference), the simple (unguided) rockets / RPG's will continue to "work" (even if their accuracy is degraded), as will 'wire' (i.e. fibre-optic) guided torpedoes and missiles (at least up to a 'line of sight' target)
However, automatic guidance systems are just too useful to be abandoned. So hurricane force winds and crippling levels of EMI will just be a 'challenge' that will be addressed, and without doubt some solutions will be found (even if some sort of 'organic' based guidance system has to be developed = see, for example, Pigeon Guided Missiles and Bat Bombs). So we can conclude that the following are missing :-
Short range unguided rockets - infantry anti-tank, ground to ground bombardment, air-to-ground etc.
Short range guided - anti-aircraft
Long range guided - cruise missiles
(plus launchers and vehicles to carry the above)
Scouting
No matter how good your 'sensors' are, the enemy will work hard to camouflage or disguise his forces, and ultimately the only way to distinguish between 'armed insurgents' and 'goat herders' is to move forward and challenge them.
So some sort of fast moving 'scout' unit is required to 'go in and get shot at' (so it will be armoured, but not too heavily if it's to move fast - and armed, but again not too heavily since it's primary 'defense' is to run away) In CF, the 'Scouts' Unit almost does the job == but their decent 'attack' and range of 1-2 makes them much too valuable to 'throw away' scouting the enemy. So these are renamed Self Propelled Guns. This leaves a vacancy for :-
Reconnaissance aircraft
Light Tank
Armoured Car
Armed Jeep
Motorcycle
Long range weapons
Once you have located the enemy, most sane commanders would like to kill them without getting their own forces killed first :-)
So we start by using the long range stuff = Strategic Bombers, Cruise Missiles, Long Range Artillery, Rocket launchers .. and to defend against the other sides long-range units, we will use our own long-range units, as well as developing specialist 'counter force' units, such as Interceptors, Anti-aircraft missiles/guns, Anti-tank guns etc. Then, when the enemy gets a bit closer (or we get closer to them), it's time for the SPG (Self-Propelled Guns), short range artillery, mortars, unguided rockets and ground-attack aircraft When closer still it's time for the Tanks, self-propelled anti-tank guns and fixed anti-tank guns. Finally, when the enemy is right on top of us, it's the turn of the tank-traps, mines, barbed wire, anti-tank ditches and trenches (and our own RPG armed Infantry) to come into play. So we need :-
Various towed guns
Fixed gun emplacements, including coastal artillery
Transport
To reach the enemy we need to develop a means of landing troops from sea or air, fording rivers and so on. Since real infantry moves slower than tanks, they need transport. The existing Armoured Personnel Carrier (APC) is too limited. We need :-
Gliders / paratroopers
Landing Craft
Pontoon Bridges
Heavy trucks
Light trucks
Protecting your capital units
Any 'high value' (difficult to make / replace) units will always be 'protected' using lower value units.
Thus (for example) you have to be REALLY STUPID (like the British with 'Force-Z' during WW2) to send in your 'capital' ships without proper support and protection from enemy air (or submarines) attack. CF has 'Aircraft Carriers' protected by 'Gun Boats' !!!! If Aircraft Carriers exist, then so must the rest of the fleet (Destroyers, Cruisers, Battleships)
Recovery and Repair
When your own units are damaged, the faster you can recover and repair them, the faster you can get them back into the front line and the fewer replacements you need.
Recovery and Repair plainly favours the side that ends up in control of the battlefield. In WW2, initially that was the Germans. So they had plenty of practice and got so good at recovery and repair that less than 30% of 'knocked out' tanks were lost. Not that they had much choice when they had so few tanks in the first place. Later, when the Allies retained control of the battlefield, they never seemed to get the hang of it. Of course, out-producing the enemy at 11:1 means you can afford to loose at 10:1 and will still end up winning.
However on most maps the repair centre (if it exists) is usually so far from the front line that by the time your damaged units have been 'back to base for repair' the battle will be over. So we need :-
Mobile Engineering Workshops
Tank transporter