Utilised as a second striker riffing off a proper goalscorer, I'm confident we'd get the best out of his skillset. Whether we want to try out a diamond or whatever is another matter. We seem to want more wide attackers in the Mane mould, which would push Bob deeper into attacking midfield, probably not where we want him. Not as crisp a passer over distance as the likes of Phil and Adam, the more natural fits for there.
I think at least having the option to switch from that wide forward three to a strike duo could be good for us tactically in awkward games. But I think the real key is having a real classy & tenacious beast in central midfield who doesn't go into hiding, because that would provide the solid foundation for loads of different midfield and foward options, allowing us to utilise most if not all of our best creative/attacking talents. I understand the appeal of more 'balanced' midfielders like Wijnaldum, on paper, but I've seen too many matches now where he's been ineffectual or downright invisible.
If we persist with our current approach, we need players who will consistently stamp their authority on frustrating games. Can has the right can-do (heh) attitude, but isn't there yet with his vision and application (most of the time). Phil and Bob get suffocated, and suddenly it's pretty easy for the opposing team.
I'd personally look to get that spine sorted; we seem to be keen on doing it for the defence and up front, but after those I really think we need to beef up the middle. Henderson coming back isn't gona solve all our problems, he'll just add some much needed extra energy all game. Of course a readily available striker who can create half-chances for himself and consistently convert would be a godsend for us, but if we want to unleash our full attacking potential with that added, we need that central defence and midfield to be smart, muscular and ambitious.
Also, width from our wingy types and full backs is only so useful if you really attack that box. You rarely see that from us, we don't really like to do the basic effective stuff even when it's called for. I wouln't want to see us lumping it upfield bypassing the middle, but a few good old fashioned strong heads on the end of whipped crosses wouldn't go amiss. Firmino's not bad at all in the air, and he's got fine upper body strength too, but he doesn't really make those kinds of moves often. He's an awkward player all round for us to place, to be honest, even though I want to see him start and be utilised to the fullest.