If the idea is to set up the top of your library for Estrid's Ultimate, Scroll Rack is easily the way to go. It is cheaper than Library + Archive and puts more than 2 cards on top each time. However, Land Tax doesn't seem to be that great here. Yes, with Scroll Rack it works out well to get better cards than lands, but putting lands on top isn't what Estrid wants. It does seem that Estrid and Scroll Rack/Land Tax are at odds with one another but if you look at it as Scroll Rack simply working well with both, then I think it is good.
Archive and Library is just slower, although it gives you far more cards in hand. It might be worth running both "combos" to be honest as they each do different things and, again, Scroll Rack can be the main piece to set up Estrid's Ultimate. At the very least, I think Library should probably be in the deck even if you find the Archive to be too high on the mana cost.
Wow thanks for the detail break down, in this case would Scroll + Ancestral Knowledge Be a better combo? Knowledge would let you look at top 10 cards and re-arrange. Could be a good deck manipulation + filter Combo?
Ancestral Knowledge might not be bad. The main thing is that it really only works the turn you ultimate (or the turn before) unless you want to invest a lot of mana to keep it around. It likely works better as well if you are playing an Enchantress type deck since it should hopefully trigger any of your other cards that care about enchantments.
I see, thanks again! It sounds like the best combo might actually be Library + Ancestral Knowledge then, to both interact with the ultimate and during the non-ultimate card filtering
currently own a Scroll Rack
Archive and Library is just slower, although it gives you far more cards in hand. It might be worth running both "combos" to be honest as they each do different things and, again, Scroll Rack can be the main piece to set up Estrid's Ultimate. At the very least, I think Library should probably be in the deck even if you find the Archive to be too high on the mana cost.