Right, but the only reason the Swiss system works is precisely because they are smaller. Fewer factions and more money to spend. It makes the process work.
I lived there for several years and I know exactly what you are talking about. There are a billion parties (or it seems like it) while the UK tends to have more factions grouped within larger parties. That said, as an outsider, I always saw this playing out a little differently in terms of national cohesion. Die Zauberformel tends to enforce that by design.