TCG, Mana Pool, and Cardmarket choices use the same card rows
Using artifact lands like Razortide Bridge can easily cause your artifact count to grow in the opening turns
Under the current rules (as of writing this blog post) both of them would simply die as a state-based action due to the planeswalker uniqueness rule, so nothing special happens
Circle of Despairs ability, much like the original Circles of Protection, does not target
[casthaven]Entreat the Angels[/casthaven]
Once you have this army, Nematas other abilities let you make use of it, sacrificing Saprolings either to pump Nemata himself up for a lethal strike, or to draw more cards which will, more than likely, create even more Saprolings for you