A sleeper Palamedesz?

At Plückbaum, an auction house in Bonn, Germany, they sell a Dutch 17th century master, "Couple riding horses in landscape", 158 by 130 cm, estimated at 2,200 Euro.

The same composition, but a lot smaller (41 by 32 cm) and much more sketchy, was for sale at Christie's in 2005 (unsold, estimated £1,200 to £1,800). That one was said to be by Palamedes Palamedesz, a Dutch painter from about 1607-1638.

I can't find no paintings comparable to the one for sale from Palamedesz, most are much smaller and busier. Of course, if the composition of the small one is by Palamedesz, then the second argument is invalid. The size as well is hardly an argument to dismiss this one, it's just unusual but not unheard of to find large Palamedesz works. Then we are left with the style. The one for sale is clearly more finished, supporting the theory that  the small one was a preparation for a large work. But is "this" the final version or just a copy after the final version? The latter would also be interesting, but the former much more so obviously.

The one for sale is far from brilliant, but then again, we are talking Palamedesz here, not Van Dyck or other contemporaries. Someone with a lot more knowledge of Palamedesz should judge this. But it certainly makes this to me a lot more interesting than the usual anonymous work.