Question about German TB sires

Maren - what does a TB stallion have to do to be Verband approved? And what does it say, if anything, about a TB who had 3 approved (TB) sons?

Approval for TBs is performance based, just like the rest. They also have to be presented in hand, just like the rest.

Performance means mostly racing records, which up until a few years ago required a GAG of at least 80kg (that's the handicap). TBs can also be approved based on their stallion performance test scores (some TBs are entered against the usual warmblood stallions). And very few are approved based on their performance record in regular shows, which then have to match the usual Verband requirements (at least 5x 1st-3rd place at S level dressage or show jumping, and M level eventing). Stallions that were approved via regular riding horse competition include Elan xx, Heraldik xx, Cupric xx, Watermill Rolex xx and few others.

Thanks, Maren

So it wouldn't be particularly startling if a very good racehorse who sired, presumably, lots of kids, that 3 of them would also be fast enough to be accepted for Trakehner approval.

The stallion I'm thinking of is Arctenango and the reason is this guy http://www.adenastallions.com/stallions/stallion.aspx?id=Musketier - who is standing in Canada for the first time this year - stud fee $2500.

No, it wouldn't. Acatenago actually had 5 Trakehner approved sons. But he was a great sire, and this Musketier (love the name) also has a good dam!! Nice stallion!