my patio border

I’m having a patio built in the next couple of weeks using the Cambridgeshire hexagon shaped pavers. I’ve had a few estimates but have finally settled on an English bricklayer who comes very highly recommended.
A couple of questions I have to people who might have had pavers built before. He insists on pouring a foundation around the edge and then building a line of border bricks in mortar. Two of the other contractors were going to use the plastic edgers that the Cambridgehire company recommends.These are driven down by spikes but my guy insists it’s not as sturdy a job. Also part of the existing ground is concrete and the other guys were going to put the patio on top. He insists on removing the concrete cos he says any water that goes through needs a place to drain.His price isn’t much different from the other contractors and as I say he has come highly recommended but I’m still puzzled by his insistence on removing a perfectly solid concrete base. The patio itself he told me will be laid in compacted gravel, with a weed barrier then sand. In his proposal he said they will be laid approx a quarter of an inch above the border and that the compacter will take care of that. my question is what if he compacts them too much, or if they won’t go down any more cos he will have already compacted the sand etc. Just a little concerned because he’s making it sound a lot more complicated than the other guys.