7 days seemed like a perfectly reasonable time to build an RTS with our still very limited experience, at the time.
The idea of building an RTS came mainly from the theme 'rock, paper and scissors' - We believed that an RTS would be a great way to show of this idea with the idea that each unit was strong and weak against other units.
We managed to include a lot of core features that we thought we were going to miss, polish was mostly our issue and connecting some of the larger components.
Pathfinding was an issue as this jam was before the Unity Pro overhaul so we were quite limited to what was available.
While an RTS in 7 days is a perfectly attainable goal (we've seen one built in 24 hours before), choosing to make one for our second game jam was probably an overstep.
It was however very useful, while we might not have built a 'complete' game we learned a great deal.