What do you do?
Well, if you were smart you would buy two half-dozens for a total of $1.50, instead of the 2.00 dozen. Same number of eggs, just a different distribution of cartons.
Warzone Control, in FW, is similar. Since it becomes more expensive to buy system upgrades the higher the upgrade is, it is cheaper to buy a larger number of small upgrades than a small number of high upgrades.
You can see all the glorious math here. But simply put, Purchasing 5 upgrades in one system will cost you 100,000 LP. Purchasing 2 lvls in one system, and 3 in another will cost you (25K) +(45K) = 70,000 LP. Either way, you get +5 points towards Warzone Control.
The more systems you have to distribute your points, the cheaper it becomes. (Getting 5 points from 3 systems would cost you (10K) + (25K) +(25K) = 60,000 LP.)
The more space you own in FW, the cheaper it is to reach and maintain a given Warzone Control tier.