First two....not a great choice to make. A good cover of a Maiden song I find meh, and a very generic Sabaton cover of a song I really like. I'm going with Grave Digger for making something of Running Free, rather than just weakly playing a Maiden song for the heck of it.
Okay, Wrathchild next. This is really odd, it sounds pretty much like the original, but with a nod to black metal vocals. Certainly does something to the song, but I'm not sure it really enhances anything or puts a new spin on anything, and doesn't entirely capture the original either. Just a mismatch of two styles.
Meanwhile I was thoroughly expecting Cradle of Filth's Hallowed to be awful. And the vocals are. Sounds like a child having a tantrum, or a death metal singer trying out helium for the first time. I'm going to give it to Cradle of Filth anyway, though, because I like the bit of atmosphere they add (keyboards?) and the screams. With better vocals, this could have been a really excellent cover that added a darker edge to this song.
Edit: and by 'better' I don't mean 'clean vocals'. Just a deeper growl.