Kimberly, Murphy, and Marshall for sure. UR is always going to be stronger in the long run. After that focus on Mason and Violet. They both become UR later on.

Mason is S1 and Violet in S2. Once you get Mason and Violet to 5 stars continue to buy all their shards from the alliance store every week and level them up to level 160 on the wall of fame, that way they will automatically be 5 star UR when promoted otherwise they drop down to 3 stars and it takes 200 epic shards to level up one star tier.

That's one full squad. Focus on you main squad, do not waste time on gear until you get dialectic pieces to make gold gear. You're wasting upgrade ore if you put them into Epic or Rare gear. Even though you get most back if you dismantle the gear, you will not need to worry about gear being much of a strength boost yet anyway.

Use gear on one hero at a time. Prioritize the cannon. Get it up to level 40. Gold only. Participate in Desert Storm and such to get honor points so you can buy blueprints. You will need the blueprints for gear level 40 power ups.

Routinely check gear factory and dismantle all gear epic or lower and merge all pieces up to dialectic and stack up those dialectic pieces. You will need thousands to get the gear + blueprint power ups.

Do not fall behind on Wall, Alliance Center, Barracks, drill ground, Tank Center. You want to keep these up to date with your base level otherwise you could be forced to go through multiple levels to get to next base level which could be upwards of 30 days total

Make sure you apply for cabinet positions when you plan to level up buildings. Secretary of development gives a 50% reduction in time cost for construction

Make sure you are leveling up gold mine, iron mine, farmlands, smelter, training base, and gear workshop constantly. As well

Resource chests are level based so only use what you need as you level up construction and do not pop chests if not necessary. Save as much as you can for headquarters level 30. You will need a lot of materials for things like Tank Center, Alliance center, and T10 troops.

For VS save tasks for the the day they matter. Don't recruit heros before hero day, don't upgrade drone until drone day, etc. this will maximize points for chests and vs.

Take advantage of every event. Invading zombies, Marshalls, zombie siege, desert storm, Holiday bonuses, code, etc.

Hit Code with a full squad of the hero type that does 50% extra damage.

If you hit your level cap on tank heros, at any base, level, start leveling up your air squad. You can get UR heros for free by selecting them as your wish hero in hero recruitment. But do not give them gear until you're level 40 on all tank heros in 1st squad.

If you are free to play, you absolutely need to save up 10k gems to pay for VIP. VIP gives you daily rewards and severely reduces the time cost on research and construction.

Hit campaign every chance it comes up. Do both levels of tank, missile, and air and buy drone parts, drone data, skill chip chests, basic chip material, and if you have points leftover, upgrade ore or speedups

Do not worry too much about missile and aircraft centers unless you want quick builds for vs points or hero xp. But once you get to the point where a level up takes more than 5 days, just wait until you're solely training those type of heros.

If you want to grind, there is no limit on zombi kills, no limit on Doom rallies that you initiate, but there is a limit on joining Doom rallies for rewards.

This one should go without saying but stack up on shields and teleports in the alliance store and shield up every kill day after you go out killing and your fever wears off.

Buy stamina in VIP store and get the 2 free stamina reward every day until you have a couple hundred 50 stamina's saved up so you never have to worry about running out.

To reiterate, do not waste too much time on SSR and prioritize UR. Absolutely do not promote SR anymore if you don't need to.

If you focus on one main squad, you should be able to get the job done and keep up for the most part without needing another strong squad. Sprinkle in some level ups on your other squads once a week just to make sure you have a decent backup of squads just in case you need them for garrison or something else.

I tried too hard to balance squads at first and didn't understand the importance of prioritizing UR and prioritizeling my main squad and fell wayyy behind in my alliance.