Thanks for the feedback!
What I like about the design of Protector of Aiur vs. Seasoned Marksman is that Protector of Aiur motivates Artanis to do more of what his kit tells him to do, which is to brawl with enemy Heroes. His main source of mitigation is from fighting things, which is what this talent is telling him to do as much as possible. Seasoned Marksman was a bit more blurred in this motivation because it told Artnias to go push lanes in order to gain power, which conflicted a bit with the rest of his kit. Also, we felt that the Attack Speed portion of the Seasoned Marksman talent was a bit redundant since he has a couple other ways to get that bonus in other talents. Removing it allows us to focus his Level 1 talent better and to let the other talents shine more that allow him to gain that buff.
Also as a side note, it’s fairly unlikely we’ll add Healing to Artanis. In general, consistently generated shields or Armor mitigation + healing is an incredibly strong combination that can easily become overpowered, and it’s something we have to be very careful about. Putting both mechanics on one hero greatly increases the risk that situations can occur where they cannot be killed.