The Blue clearly makes the populate mechanic better because you have better targets by virtue of Blue having the easiest time turning creatures into tokens, but I submit that Blue makes the rest of the deck better
1998 Pokemon Commissioned Presentation Galaxy Star Hologram Blastoise CGC 8.5: $360,000 Wizards of the Coast commissioned the printing of this Blastoise card ahead of their presentation to secure English printing rights from Nintendo
Fun fact: Tsunekazu Ishihara has been the President and CEO of The Pokmon Company and he gave away several copies of the promo to select colleagues, friends, and staff at his 60th birthday party celebration in 2018
Now, I need to point out a few of Espeon ex Teras shortcomings
While its restriction to only collecting low-power creatures can be awkward, you'd typically include Kiki-Jiki, Mirror Breaker alongside Imperial Recruiter, to trigger Recruiter's ability many more times
Pyro/Effect