While this used to be a rather rare effect, with the popularity of commanders like Emmara, Soul of the AccordEmmara, Soul of the Accord and Magda, Brazen OutlawMagda, Brazen Outlaw, it's a space that's gotten a lot more exploration in the last year or three
On its early turns, it doesn't seem to achieve much - play a land, fetch a land, create a puny plant token
It makes up for the narrower scope with its warp ability and lower mana value
If all he does is keep you from taking damage for a couple of turns, isn't that a worthwhile investment of 3 mana while you set up the rest of your fort
At most, keep around 8 cards total in each pocket so that you can easily pulls cards in and out
A 4/4 that hits as an 8/8 is usually good before you even consider its all-natural trample and permanent mass pump effect