I spoke to a farmer who grows wild flowers over a couple of acres.
He first said it wasn't much work.
Then followed it up with what he actually does, which was to re balance the seed mix each year. Based on the previous years display.
Plus after quite a few years of trying to get the 'perfect' mix, which generally means more poppies, corn flower and corn cockle, he found they just fade out of the mix, leaving the more aggressive and not so eye catching flowers.
So even though he knew his soil type, and what flowers liked to grow there, he couldn't guarantee what flowers would thrive.
His answer was to put a bigger percentage of the seeds he wanted into the mix and hope.
But even then, he had plug plants of the type he wanted waiting to address any shortages.
He concluded that on balance it takes just the same amount of effort to grow wild flowers as any other crop, just a different approach!