Things that are good to know before MP

[Bavre]

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Remember, you can always move a HQ and then attach units to it (including units that just came into command range)
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As a little addon: You can even operate an HQ and then attach units to it. After operating just switch its command mode to "reset" it (the command mode can be switched back and forth as many times as you want, so you can e.g. go semi automatic->manual->semi automatic)
If the HQ does not have spare capacity, you can also disconnect units at its old location, provided those units have not done anything yet.