Well said and that's all logical and makes sense... but you have to view how they'll likely deal with Draisaitl/Yakimov through the filter of the management group of a team that's missed the playoffs for 8 years straight and has been in the bottom 7 teams in the league for 5 years straight.
Logic and common sense isn't something that's very common within this management group.
My bet is they will keep Arcobello and Lander up (because they don't want to risk losing either to waivers) and give Draisaitl his 9 game look. They'll likely start Yakimov in the AHL... again moreso because they don't want to dump either Lander or Arcobello on waivers until they see what Yakimov/Draisaitl can do against "real" AHL/NHL teams in a larger sample of games.
My gut feeling is they'll probably keep Draisaitl up for the full year... I don't think he'll **** the bed bad enough that management will want to send him overseas to Europe where the gameplay is quite different than the NHL style of play. It doesn't sound like Leon is overly enthusiastic about going back to Junior.
If Yak2 rips it up in the AHL he'll likely be the 1st injury callup part way through the season... and then the Oilers will likely dump either Lander or Arcobello on waivers (whomever is playing poorer at that point)... or they make a minor deal with another team for a late draft pick more likely instead of losing them outright for nothing.