I read that as that's the most they think they'd ever get. Four is fine if we see 3-4 cars per manufacturer, and plenty of privateers; meaning we see 15-20 Rally 1 cars. As he says, six or seven can become unsustainable as they can't all win - and some end up pulling out. We saw that in the early/mid 00's.

I'm wondering how long the WEC manages to keep all their new manufacturers in the next few years.