I only read the first short story so far - the Christmas one - and will leave the second one until the right time in the story line.
The Christmas story has its moments, but like any short story there's not much to it. The temporary characters felt more two-dimensional than usual, more like caricatures than the usual depth Cornwell brings to this series. Again, it's a short story so there isn't room for depth, but the whole reason I usually love the Sharpe books is that depth.
This one was a bit meh so I'm giving it 2.5 stars. I'd say diehard Sharpe fans can read it for a brief amusement but unless something comes up further down the line, I doubt this will be meaningful in the overall Sharpe saga.