I would fully expect to see 22 different players getting a start between these 2 matches. Wouldn't worry about them being on the Sat & Sun.
I would have thought that, given we'll be incorporating a new style of play, we'd want to play something approximating our first team as many times as possible personally. Koeman wasn't happy about the Dresden tournament having back to back games a couple of years ago for that reason, for example.
It could potentially also pose issues in terms of match fitness too. We currently only have 3 other friendlies scheduled (with maybe the winners of the SportPesa Cup to be added in at Goodison?). Each player getting, say, 4 preseason games doesn't particularly sound ideal to me.