I already watched the TV series (47eps) so I'll do a brief comparative of what can you find in these OVAs. The first episodes are the direct sequel of something serious that happened in the TV series. It would be the most important arc that this animated series has had. However, the rest of the episodes are simply isolated chapters that were removed from the main series as a sort of innocent fanservice. So this part is like a gift for fans that wanted to continue their lives, somehow. There's practically no more mecha action with Alphonse or any other Ingrams so don't be dissapointedfor this.