Two things here:
1. It really depends which game you're talking about. Some games are more CPU intensive, while others are more GPU intensive. You'd have to look into what FIFA is like in terms of resource usage to determine what it uses, but the rule of thumb is that your video card (and therefore the HD 3000/4000) would be a bigger bottleneck to your performance than the processor.
2. Mobile processor nomenclature is different from its desktop counterparts. For example, desktop i5s tend to run 4 cores and 4 threads while i7s tend to run 4 cores and 8 threads. Those laptops, however, are probably running something like an i3-3217u or i7-3537u, both of which are very mediocre processors that each run 2 cores and 4 threads. Thus, you won't really get much more performance out of that i7 than that i3.
In short, go with the i3 with the HD 4000 over the i7 with the HD 3000.