From: Leeuwarden, Netherlands
" How would the distribution of supplies and HQ bonuses work then? "
Supply flows automatically, no need for trucks or horses for that, as long as the distance from your railnetwork isn't too great all units get their supply. So from there it follows that engineers can be your most important units, they build the railroads. No railroads no supply, no supply no army. You can see that for yourself when you send a unit far ahead, say a cavalry unit, at one point the supply dot on the counter will turn yellow and then red.. time to get back home :-)
HQ bonus is simple, as long as a units HQ is within 3 hexes it gets 100% bonus (oh and make sure that HQ is filled to 100% staff) every hex added is 20% less HQ bonus. Other HQ's or SHQ's don't count in this case, they don't give a HQ bonus to other units... easilly discernable by the coloured bar on the unit counter. Did you know you can change that colour too? Just click on that coloured bar on the HQ and a popup appears, you can then choose any colour you want.