I doubt you'd snag more than 1 very often, and almost never get 3 like I did in that mock. It's risky in that respect. But the creature part is fairly easy. Lot of commons in U/W/G/B that have big butts. Almost every UW draft or sealed deck I've watched videos on in the last few days have snagged/run a copy or two of the 2/5 unblockable vigilance dood. If only one High Alert is picked up, you'd have to go Esper to win with a more defensive build when you don't draw Alert. I've been seeing I'll-Gotten Gains pick up wins in those types of deck. Like any forced archetype it'd carry risk as a 1st pick - but if pack 1 was mediocre, I'd try it.

In Bo1, you'll rarely see enchantment hate. Mortify is of course an auto include in any BW/X deck, but it's a rare. This set doesn't have a wealth of versatile options like Guilds' Conclave Tribunal, Crushing Canopy, and Sprouting Renewal at uncommon/common that can make the cut for their greater utility - along with Knight of Autumn AND Assassin's Trophy at rare. The common/uncommon enchantment hate options in Allegiance don't have the versatility to make Bo1 inclusion worthwhile.