The best solution for a potential client might be that you don’t take the job.
They might think that you are. They might think that they need whatever they say they do.
But, it’s not your job to accept that just because that’s what they’ve said — even if it results in a paycheck for you.
If your experience tells you that they need something else to achieve their goals, that’s exactly what you should tell them.
Of course, you can take the job and maybe you execute for them but, in the long run, you’ve helped yourself more than you’ve helped them.