It is true that FNV and RGLD will monitor all compeitors and consider buying them out under certain circumstances.
One reason would be to eliminate a competitor if that rival (example SSL) was taking away business or depressing the royalty margins
The other reason would be to make an acquisition that would instantly be accretative to shareholders.
SSL has created a big barrier to block the likelihood of this happening. By having great management and a well known leader SSL already trades at high multiples and it has a high NAV.
An acquirer would normally fight to get a 30% premium to the share price but this would mean that teh buyer would pay a much higher valuation than FNV or RGLD enjoys on their own existing business.
My prediction. A takeover of SSL will not happen unless they run into trouble and the valuation drops. SSL will continue to do very well as a stand-alone business