I agree with sending to the trainer focusing on transitions if you're thinking of sending him away.

Do you think it's confusing to use 2 different trainers?

Usually not, depends on the horse, the trainers and the rider.
I want a horse that can do lots of different things I ask: Western jogging in the arena one day, dressage another, long trotting down the trail with no contact another day. He can handle it.
If your horse can't handle both now, then choose one and introduce the other later when the horse can handle it.