I had fond memories of that title and I bought the Essential collection. As a European, I may be more interested in stories featuring villains than Americans. This is a long tradition in Europe: Fantomas, Arsene Lupin, Diabolik, The Spider. Even le Comte de Monte Cristo is ambiguous. Marvel had tried the potential of Dr. Doom for a long time: he was the feature of his own story in Fantastic Four Annual #2, then in Marvel Super-Heroes #20. His half-feature in Astonishing Tales has beautiful art by Wally Wood but uninspired script by Roy Thomas and Larry Lieber. There was an inspired story by Gerry Conway and Gene Colan in #8 that highlighted the tragic dimension of the character who wants to save the soul of his mother from hell but it was too late. Hos co-feature Ka-Zar had proved more successful, probably due to the revival of pulp stories heralded by Conan, and would take over the whole magazine.
In 1974, Roy Thomas would herefore launch a new concept. It was his job as head writer/editor to do so. The Sub-Mariner title had been cancelled (despite a change of costume) with dangling plot lines: all the Atlanteans were in suspended animation, some humans (including Betty Dean) had been turned amphibious against their will, and a beautiful alien called Tamara was stranded on Earth's oceans, the last of her species.
An alliance between Namor and Dr. Doom had been used as a plot ever since Lee and Kirby used it in the first super-villain team-up in FF #6. Roy Thomas had used it in Sub-Mariner #20 and Gerry Conway in #47-49. Roy Thomas had already been behind the use of Sub-Mariner in the Defenders, following from a crossover storyline created when Dr. Strange had been cancelled (after he changed his costume).
So Thomas launched Super-Villain Team-Up. The title would mostly follow the storylines from Sub-Mariner though elements from Astonishing Tales would show up too.
Yet the title's history would be marred with creative musical chairs. Writer/editor Thomas and John Buscema launched the first Giant-Size issue which was mostly made of a reprint of Sub-Mariner #20 (also by Thomas and Buscema) and Marvel Super-Heroes #20 (by Thomas and Larry Lieber). The second issue has horrible art by Mike Sekowsky.
Then the regular series starts with Tony Isabella under editor Len Wein, with a sequence pencilled by Tuska and Bill Everett plus a story by George Evans that probably came from the cancelled Sub-Mariner series (no Dr. Doom mention).
The second issue has pencilers Sal Buscema and Fred Kida as well as the death of Betty Dean. By then Dorma and captain Leonard McKenzie had died. Unfortunately the trend of killing Namor's supporting characters has continued, effectively destroying the character.
Issue 3 has a new writer Jim Shooter under a new editor Marv Wolman (until #7) and the return of penciler George Evans. Jim Shooter's writing has a hard edge to it uncommon in Marvel Comics of this time: Tamara is tortured, Doom murders people, Dr. Dorcas is crushed to death.
Issue 4 has a new writer, Bill Mantlo (who will be one of the most regular but not yet) and a new penciler, Herb Trimpe (who will also be one of the most regular) with inker Jim Mooney who had inked the Sub-Mariner series. There is a link with the Deathlok series and his is one of the most peculiar things of Marvel in the 70s: in spite of the musical chairs, there was a better continuity than in the 80s and later.
In issue 5 arrived new writer Steve Englehart who will stay until 8 (a record). Englehart gets rid of the new Sub-Mariner costume and introduced a Batman doppleganger (the Shroud) probably trying out for DC Comics (where he will indeed do a great Batman with Marshall Rogers).
In issue 6 Englehart introduced politics in that the US signs a non-agression pact with Latveria so that super-heroes can't intervene there. No writer will expand on Englehart's ideas until Alan Moore in Watchmen.
Issue 8 sees a new editor Archie Goodwin (until #14) and new penciler: Keith Giffen. Steve Englehart leaves which is probably why the title started to crossover with Avengers 154 and 155 (by Gerry Conway, George Perez and Pablo Marcos).
Issue 9 has Bill Mantlo as writer who will stay until issue 14 (a new record) and penciler Jim Shooter. Both are known (with Sal Buscema) for their ability to work very fast, which explains many things.
Avengers 156 is by writer Jim Shooter and artist Sal Buscema (with a plot by Conway) and is the end of that crossover.
With SVTU 10 we have new artist Bob Hall who will stay a regular until the end but little else will be regular. The story has the Red Skull and marks his prominence in the title since he is co-featured with Doom in 11 and 12 (Sub-Mariner is still there). 12 is the last appearance of the Shroud.
In 13 Sub-Mariner is back as a co-feature in a story penciled by guest artist and co-plotter Keith Giffen which marks the end of the Atlanteans in suspended animation subplot. They are revived and the story continues with Giffen in Defenders. This is the end of the alliance between Doom and Namor.
Issue 14 (by Mantlo and Hall) features Doom and Magneto and concludes in Champions 16 (same creative team). The title stops there with a reprint of Astonishing Tales 4-5 (Red Skull vs Doom).
It picks up one year later with the Red Skull and Hate-Monger in a two-part story tying up a lot of loose continuity.
This is the index of writers, pencilers and inkers for this collection. It shows there are mainstays in spite of the musical chairs.
Roy Thomas MSH 20, Sub 20, AT 1-2, GSVTU 1-2
Larry Lieber MSH 20 AT 3-6
Wally Wood AT 1-4
George Tuska AT 5-6, SVTU 1
Mike Esposito AT 5-6 Champions 16
Gene Colan AT 7-8
Gerry Conway AT 7-8, Av 154-156
Frank Giacoia MSH 20, AT 7
Tom Palmer AT 8
John Buscema GSVTU 1, Sub 20
Joe Sinnott GSVTU 1
Vince Colletta MSH 20
Mike Sekowky GSVTU 2
Sam Grainger GSVTU 2
Tony Isabella SVTU 1-2
Fred Kida SVTU 1-2
Bill Everett SVTU 1
George Evans SVTU 1,3
Frank Springer SVTU 1
Sal Buscema SVTU 2 Av 156
Jim Shooter SVTU 3,9 Av 156
Jack Abel SVTU 3,6
Bill Mantlo SVTU 4,9-14 Champions 16
Herb Trimpe SVTU 4
Jim Mooney SVTU 4
Steve Englehart SVTU 5-8
Don Perlin SVTU 5,10-14
Pablo Marcos SVTU 7, Av 154-156
Keith Giffen SVTU 8,13
George Perez Av 154-155
Sal Trapani SVTU 9
Bob Hall SVTU 10-12,14 Champions 16
Peter Gillis SVTU 16-17
Carmine Infantino SVTU 16
Bruce Patterson SVTU 16-17
Arvell Jones SVTU 17