Assumptions in Wireless Sensor Networks (WSNs)

I have been doing a fair bit of reading in the area of wireless sensor networks (WSNs) as a part of my work as a research associate on the DIAS project. It is interesting to note how few WSN papers actually deal with real problems. I should do a survey of my current literature holdings and determine how many of them are grounded in an actual problem that the authors were trying to solve.

For example, consider this snippet:

The authors assume you have enough nodes in your network to form clusters. Most of the deployments I have to consider aren't going to have a budget large enough to deploy so many nodes that we can form clusters. So, what do I do if I'm developing a four-node network? What use is this algorithm to me? Do I let four nodes duke it out for the role of "cluster head", even though I already know the node with the GSM radio (read: mobile phone) is going to be in charge?

Assumptions are dangerous things.