The article says "Intel’s dominance in the global microprocessor market is being threatened by the rapid rise of ARM Holdings.".
ARM Holdings might be "rising rapidly" today but it was founded in 1990. They've been doing ARM processors with the exact same business model for the past 20 years.
The reason they're successful today is simply because they have superior technology in an area (power consumption) that is important for a quickly growing mobile markets.
Arguably ARM was a better architecture than x86 from the beginning but it didn't matter: after Windows/x86 got majority of the market share, the switching cost for a different processor were too big and Intel was doing a good job driving x86 in ways that mattered for that market (performance).
Only when a completely new market emerged (for PDAs, iPods and cell-phones) that was free from requirement to support legacy code, ARM found it's place because it delivered one thing much better than Intel with their existing line of x86 processors: power consumption was dramatically lower. It also happens that this was a core requirement for mobile devices.
We can't go back in time and see how ARM Holdings would hold up if they were doing their own manufacturing as well, but in my opinion the business model has a minor impact on their current success.
The most important thing is that they have a product that is superior to competition.