A distress post！

I have been playing this game aimlessly for a long time, until someone told me that you should focus on one unit in order to become stronger. Suddenly, I realized that my main account was already in a mess. I tried to use a new account to exercise, but I still wanted to quickly unlock T4 and castle level 25. The problem I faced was that my stones, iron ore, and coins were often not enough, but other resources were already exceeded. I have many questions, but I don't have any friends playing this game. In addition, the language barrier (translation software is good, but communication is difficult) and everyone's online time is not the same. If there are experienced players and you have enough time, you can help me answer a few questions:

1. When did you start confirming which unit to play? Or based on my own preferences, I obtained the blueprint through a bounty mission and was fortunate enough to wield a sword with a level of SS. Can I confirm the type of troops based on his attributes? I don't really like any soldiers, I feel they're all similar. Besides, how do I match a commander?

2. If the type of troops is confirmed, should archers be placed on the city wall defense or your own strongest type of troops? If you play spear, you will definitely not be able to defeat shield players,

3. Regarding the selection of hospitals, gold mines, and tents?

4. For technology, should we unlock T4 first and ignore everything else?

5. Which military unit do you prefer?

Best wishes!