I was shocked to read he only had 630 hours in all those years! that flagged up problems
No, gliding hours are usually discounted in reports abut commercial pilots. He had 630 hours on A320 since he started his typerating in summer 2013. That is not unusual, but on the low side. There are others that fly even less. For the last 8 years or so i average only around 300 hours a year flying full time in airline operations.
He started gliding at age 14 or 15 and has glided ever since, last year he did apparently only 20 hours of gliding, but for someone working in the airlines that is not unusual as most gliding clubs only have flight operation during the weekend which is not always easy if you work most weekends.