Only reason that worked in SupCom is becuase you can build huge armies, alot of units die fast, and you don't really have alimit on how much resources you can get. Build enough Mass Fabricators and Power Generatiors and you can pump out units as fast as you please.
Uh, for all intents and purposes there's no distinction with Sins there. If you have enough trade ports, you can effectively have all the money you will ever need in Sins. Resources never deplete in Sins, either. There are two key differences between the games that affect this issue.
The first is in the way the costs are paid. In Sins, we have to pay a lump "up front" cost for our units before the factory can begin producing them. In SupCom, you pay money over time as the unit is produced, and production halts if this cost cannot be paid. This means that in SupCom we can very easily analyze our expenditure versus income. In Sins, that's more difficult with costs popping up in huge and spontaneous lump sums.
The second issue is in the determinant factor of affordability. In Sins, individual units are quite expensive, and most of your time will be spent waiting for the cash to build up to use your factories. As an aside, the factories themselves are inexpensive. In SupCom, factories take quite a while to complete their units, so the dominant factor of affordability there isn't the cost, but rather manufacturing infrastrure.
In Sins, we may have five or six factories, but at any given time we may only use one or two of them (the ones closest to the battlefield). Moreover, even when we are actively using a factory, it may only be producing units half of the time. The result is that 90% of our industrial capacity is usually idle, and simply left as a tactical reserve so we can produce a fleet quickly at the designated locations. This is quite the opposite in SupCom, where under ideal circumstances a factory is almost never idle.