ok this is how resources works (fuel/popcap/ammo)
Frank fuel 0
red fuel 0
koops fuel 0
ads fuel 0
+16 fuel captured by frank (the +xx refers to amount per min of that resource). From this you can calculate how far away from tanks you are. ie. requires 90 fuel for tank depot so that 5.5 mins with only 16 fuel.
1 min later
Frank fuel 16
red fuel 16
koops fuel 16
ads fuel 16
another minute later
Frank decides to add flamethrowers to his engies to deal with some particular unit(cant remember exact cost lets say 16)
Frank fuel 16
red fuel 32
koops fuel 32
ads fuel 32
Resources are EARNED as a group and spent as an individual. If it wasn't then you'd be saving for something specific. ie. tank depot. Yet someone could keep spamming flaming engineers and you'd never get to tanks.
The same applies for popcap. The total is EARNED by the team and spent by the individual. If your at popcap limit and a unit *almost* finished it meant that you re-enforced somewhere that stole the population that unit required to be allowed onto the field. When either more territory was captured or more of your men died meant that your current population was less than total pop allowing the unit to finish production.
If you want to understand this better re-watch one of our games (if you saved it). From memory you should be able to choose whose perspective you watch from thus can see what their stats were at the time.
oh .. handy link for costs here -> http://www.coh-stats.com/