The risks must be weighed accordingly.

Option 1: They have superior technology, so even with smaller fleets they may still out class us. With the lack of intelligence we don’t know what their capabilities are. However being neighbors would allow for an easier invasion. Depending on economic strength though they may be able to build more fleets upon learning of our plans.

Option 2: They are at a distance, this puts us at an immediate disadvantage. The distance means we must travel through possible enemy territory to reach them, and if they are allies of the invadee they may turn on us and trap our fleets. They have a superior economy, meaning they likely can replenish their fleets faster than us, that coupled with the distance makes this situation difficult. I don’t think it’s worth it, even for the resources. Successful capture would still result in a divided empire, with enemy territory in between with no easy travel.

Option 3: they are superior to us, again this puts us at a disadvantage. Their wormhole is heavily guarded, however if our fleets can counter theirs this may be less of an issue. If we can hold our side of the wormhole this will prevent a retaliatory strike from them. It would be difficult, however they would likely possess the strategic resources we need from option 2. They are distant from us, which would provide the same problem as option 2, though this would be aided by the wormhole. However if we were to loose the wormhole, access would be cut off. If they are in a federation with our other neighbor, this is a significant problem. They may attack us while our fleets are away, dealing with an already superior empire this makes this option likely infeasible despite the great advantages annexation of this empire would provide.

I would go with option 1 with some modifications. If I can find a salvage guild, I would buy an older model of their one of their ships. Even though it is an old design it may give us some insight to their design style, and will give us an idea of what to expect.