The Obvious Answer The biggest issue to Gallifrey Stands, besides actually getting all but one of the Doctors on the battlefield, is somehow untapping with your board
Allen Wu In addition to his three Grand Prix victories from his four Top 8s, Allen Wu had two previous Top Finishes to his career: victory alongside his winning teammates Greg Orange and Ben Hull at Pro Tour 25th Anniversary and his Top 8 at Players Tour Phoenix earlier this year with a dominant 14-1-1 record
That way, you can kill an opponents creature and get to kill one of your own
Foxglove is oft declared the adventurer "most likely to win your heart" by various guilds across Valley
You'll also churn out a Bat for the Bone Dragon itself, by the by
The first chapter deals one damage to each opponent and each Planeswalker they control, and the second gives the next creature spell you cast during your turn a +1/+1 counter