The way i see it, is that there are differences in what you want out of a Center/Forward in different roles.
With a true #3C, you want a guy who is able to take on tough matchup minutes and anchor a line while still chipping in offense.
With a #4C, the prototypical guy is some combination of big/physical/fast/pesty and can make their impact with those limited minutes. DZone starts, winning faceoffs, killing penalties. Creating "energy" by generating a sustained forecheck with simple, straightforward, "get the puck below the hashmarks and mash it into the net or jump on broken plays" sort of minutes. Really good 4th liners make their limited EV minutes count by playing a game that doesn't need them to handle the puck a lot or get creative with it to be effective. Then expand their impact on the PK. The reality of 4th line EV minutes is that a player is going to go long stretches of time without ever touching the ice, much less the puck. Offensive-oriented players can't ever get into a rhythm in that mode.
Pius Suter is one of those players who falls in a sort of awkward no-mans-land as a sort of "tweener" amongst a few different things.
He has okay offensive skills. Enough juice on the
offensive end to be a 3C...but he's not anything like a "matchup center". So if you've got a solid roster, you don't actually want him as your #3C. His defensive mediocrity means he's not anything like the anchor of a stout 3rd line which means you're having to dump off those hard minutes on your Top-6 and 4th Line to "shelter" them. However, those offensive skills make him a candidate for temporary stopgap promotion into the Top-6, ideally as a winger though. Over other Bottom-6 types.
However, he isn't big, fast, physical, or impactful in the sense of typical 4th line player though. Which is where there's a clear split. He's a guy who needs to be in a generally cushy "offensive minutes" role to really thrive. Put him on a crash and bang low minutes 4th line and he'll offer next to nothing. This makes him...
not a 4C.
That's what makes him more of a so-called 5C. Where you don't really want him in any role from #1/2/3/4C if you're building a conventional contending roster. He's not really cut out for any of them. Placing him anywhere there, reframes and places additional responsibility on some other role.
That's where he's in an awkward "tweener" realm as a guy who i'd actually personally characterize as a "Top-9" Filler...or a #5C. Or maybe even call him a #2f Center. Where he profiles a lot more like a Top-6C and has had most of his production there. But if he's in your Top-6, your Top-6 sucks donkey nuts.
You have to open up the brainbox and start to think critically about roles and practicalities. Rather than thinking about #1/2/3/4C as a strict hierarchy of scoring ability or "pure skill". You have to think like a coach, in who you'd want to send over the boards to be effective in a particular role to make your life easier and your team more successful.
We've been down this road before. There are ways to make it work. Santorelli was beloved here because he had a good stint as a cushy Top-6W. Similar sort of player but less dynamic. Washed out of the league fairly quickly. Jeff Tambellini was a similar player for us too. Where he could play as the "4c" when someone like Manny/Lappy was there to do the heavy lifting ahead of him.
I think that's where this Pius Suter signing
could work out. If Bluegers proves he can still be that counterpart in a split role 3a/3b sort of line composition.
But the reality is...Pius Suter is
not a #3C. There's a reason he was left hanging well into August as a free agent. There's a reason the Blackhawks let him go. He's a tweener sort of player. Just so happens that we may actually have room for a "tweener" like him while trying to make this bizarrely constructed roster work.