Honestly I'm hoping that, regardless of what Feige has said about both movies, they are pretty connected and this movie is mostly used to establish Thanos and the Order(Children of Thanos for MContinUity's sake). They can be offed in A4, but I think a big part of making Thanos seem invincible would be having his lackeys be the biggest challenge the Avenger have faced. If they have trouble with people who bow to him, imagine what he has in store for them. It would kinda be a shame if they were introduced and offed in 1 movie, to me anyway.