Too much redundancy with all three. I'd say Swisstool and fixed blade is more then good. I wouldn't trust a slip joint and the SwissTool has so many more capabilities.
I've had a Swisschamp since 1993, for many of those years my only pocketknife. From that experience I believe the champ is at its best in an urban environment. Out in the boonies things get a little more elemental. There, strength and simplicity have an advantage over clever and complex. This is not to say the Swisschamp is fragile, but bigger is better. Also, it can be a real comfort to have good size, usable pliers on hand.
In the city, you seldom need tweezers; in the woods another story. Dedicated ones take up little space and are way more effective than the "better than nothing" SAKs, and you can whittle your own toothpick. That little magnifier might come in handy here and there, but don't think of it as an emergency fire starter. Except for giving an unsuspecting buddy a hot spot

, the glass is too small. I have heard about some successes, but neither I nor anyone I know has had any luck in years of trying.
The SAK does small camp chores reasonably well, but scaling fish is how I learned some of its limitations. It took me several sessions to clean it out and smelled bad for days :barf: . Smeared with mud and stuff too terrible to mention made for a gritty, hard to open and close implements until you can do maintenance. A larger tool can swallow more dirt and is easier to clean.
But I will say this; if I didn't own a pliers based multitool, I would without hesitation take the champ into the woods, and in fact have done so many times. Slip joints are fine, handled properly.