For a new starter, don't mix tyres.
I recommend the Metzeler Roadtec 01, or Michelin Pilot Road 5 (3 or 4 are also good, but old stock). It'll feel like another new bike then and will be a big confidence booster, enjoy it.
Note that the above are touring tyres, so you will need to tailor your grip expectations accordingly. I currently run the Roadtec 01's and they're decent for road use.
It's his first bike, any new tyres will be great.
It's still worth mentioning. I got the stickiest rubber (for cold tyre and rain performance) I could on my first bike to minimise any risks.
Modern tyres like the PR5 will have more grip than a new rider could ever possibly use, and will have more grip in less than optimal conditions. Really sticky don't tend to work well until warmed up and tend not to be so good in the wet.
I got the stickiest rubber (for cold tyre and rain performance) I could
Diverging from the OP a bit, but my experience is different.They definitely don't grip as well as the M7RRs in the wet. There's a reason I specifically said:
Couldn't expect a new rider to be pushing tyres that much, so a modern sports touring tyre which is predictable across all conditions and heat up quickly is more suitable.