The reason why it would be so great if both of them were added is the following: normal summon princess, search and set onslaught, attack with princess, princess's effect activates, discard baby tiger, S. summon queen from deck, baby tiger's effect activates & s. summons itself from grave, and because queen is on the field it doesnt matter if the opponent has a higher atk monster than princess.
In continuation with my previous comment, since princess ups the deck's consistency, you could use holy guard, meaning that you wouldnt lose any lp if you attack something big either. Note how this entire combo requires you only needing ONE CARD in your hand to pull off
...oops, I realize how dumb my previous comment sounded lol. It requires only one card if you already have a baby tiger in your GY, since you can either discard or tribute a monster for amazoness princess's effect to S. Summon an amazoness from the deck. Still, even if it technically* requires 2 cards, its still really consistent to pull of in a 20 card deck