Even with wide men like Martinelli and Saka - speed, flair and goal threat - I absolutely cannot be doing with a striker that can't run.
That said, I think your definition of a striker is a little too narrow. They don't all have to be Thierry Henry in terms of quality, impact and style. Firmino is a bit of a plodder in some ways, for example, and quite similar to Lacazette really, as has been discussed here before, and yet it works for Liverpool in their set-up. Salah and Mané are the "Henrys" of the team.
I think Martinelli and Saka are good enough for something similar to work here, even if it's not to my taste.