Infanrty: Alot of Regular Infantry, some Motorized Infantry and maybe a few Mechanized Infantry. A few paratroopers are also realistic.

Ordnance: Steady amount of all ordnance, exept SP. bit less from that.

Armor: A shit ton of light tank, a good amount of medium tanks and a fair amount of heavy tanks and Tank destroyers. Some armored cars to combine them with your infantry.

Aircraft: A good amount of Fighters, Attack Bombers and Tactical Bombers.

Navy: 1x lvl4 Battleship (bismarck). Just a few battleships, no aircraft carriers, and a steady amount of cruisers and destroyers. A crazy amount of subs though.

Secret: A few railroad guns, a bunch of rockets/flying bombs and almost to none rocket fighters, somewhere in the late game. Not to much but also not to less of the Rocket Artillery.

Based on the axis doctrine, my tactics is (and has been tested): Infantry: Prioritize on motorized infantry, accompany it with arty (SP preferred) or fast tanks. You will also want a mix of infantry. Militia should be left at lvl. 1 to defend the homeland in emergencies, and don't bother with paratroopers nor commandos. Ordnance: everything, you want them, ranged attacks are your best attacks, make sure to utilize your broken attack values to tanks with your towed anti-tank and aa. Have some SPAA with your big units since experienced players will and most likely will use planes, and your units are extra expensive. Tanks: Prioritize Light and Medium tanks, they are the fastest and the cheapest (Medium tanks are as fast as light tanks in axis) have some heavy tanks and pair them with mech. inf for defense. And very few armored cars or tank destroyers. Aircraft: Focus on attack and tactical bombers and pair them 10+10 for maximum damage in late game, if on large maps, focus on fighters too. Navy: Submarines are your friend, scatter them throughout your kingdom and have some surface ships. Secret: Since rares are cheap in 1.5, use them, have rocket arty (both types) with your main force. Have rockets to kill your enemy's airfields and maybe jet fighters if playing small maps. Invest in railroad guns if you feel that they will come in handy, and make sure to utilize their range by pairing them with armored cars or motorized infantry, as well as aa to protect them.

Man I don't know about that advice. I have had great success with these units as Axis and being able to focus upgrades only on these units:

Stack up for attacking:
- Medium tanks
- Mot. infantry
- SP artillery

Support attacks with:
- Tac bombers
- Throw in a couple of interceptors

Navy:
- spam subs (Axis have good submarines)

At your home defense:
- cheap ordinace probably only level 2 and MAYBE 3
- Artillery, anti-tank and anti-air
- couple of level 2 or 3 infantry

a nice addition to your machanised forces are SP AA, Keep some commandos as well.
I suggest building units on where they are going to be stationed, Artillery for mountains, SP artillery for plains

Nah the advice here will have you spending all your resources on research and upgrading. You need to pick 2 things you like per factory type and one of those stays at lower rank.

I've learned the hard way to really pick just a few of the main country's doctrine units and focus on their research upgrades. I try to research upgrade all units but it ending soaking up too many resources and I waste all that time doing it.

This is the pretty much the perfect unit combo for axis. Due to the heavy costs, as axis it is vital to balance resources or else you army will run out of units.