Help Designing University Apple Tree Guild

I’m a new student lead working on my university’s gardens, but I know very little about gardening!

I’m looking to create a guild for some apple trees that have just been planted on a small hill we have and I just want to make sure I’ve got everything right. Last week, I got started and planted a few different herbs and perennial plants around the trees, with the hope of continually adding over time as I learn.

But I have recently seen a post that says I must control the grasses or my guild will fail. I have now researched and have found 6 plants that I think will serve as a great guild matrix of ground cover plants. comfrey, yarrow, chives , thyme, or oregano, clover, nasturtium

I was thinking that first, I would go charles dowding style. I’d chop the grasses down, place a tight layer of carboard on top and then a layer of compost and plant my plants directly into this to hopefully provide some good soil fertility and to suppress the grass/weed species. Is there any problems with me doing this?

And for general design, I was thinking a row of oregano/thyme as fortress plants to keep out the weeds on the front edge. Since the other sides are surrounded by concrete do I still need to protect them?

For the yarrow and clover – I was thinking of placing it around the guild in clumps so that they would hopefully help eachother take off and build a good croundcover.

The chives I think I will place dotted around near the trees to hopefully help prevent disease. And the comfrey I will dot around solo so they do not take over the garden.

Thanks in advance for your help – literally any advice will do – I want to make sure I get this right so that I can advocate for this idea with confidence to my university. Of most concern is how I prep the bed (no dig etc) and how I go about designing the edges to keep weeds out.

Cheers

face where the apple trees have been planted