New-ish Player here. Just spent hours trying to complete the Starter Deck Duels. Letting off steam by ranking them all based on how much they frustrated me.
Basically this is ranked in order of worst to best, so I'll just present them in countdown format.
(note: please don't mistake frustration for not having fun. the game is a blast and I'm excited to jump back in.)
C-TIER
10. Morbid Machinations (BG / Golgari / ⚫🟢)
For a beginner, the whole concept of having your creatures need to die so that you can become more powerful felt a bit counter-intuitive. Though when I played it enough, it became clear which were the expendable bodies and what spells benefited from them. It's a very slow and grindy deck. Felt like you needed to do a handful of clever combos to achieve roughly what another deck can do by just casting a couple of good creatures.
9. Wondrous Wizardry (UR / Izzet / 🔵🔴)
Another slow-burn deck that seemed to rely more on getting it's machinery running than other decks. Sometimes you feel like a genius chaining spells together, but a lot of times you're realizing that your opponent just played a 4/4 and all you can answer with is an Opt.
8. Graveyard Gifts (UB / Dimir / 🔵⚫)
This one actually felt like the most awful at first. I needed to really wrap my head around the idea that the graveyard was indeed just as valuable as a resource as my hand (derp, it says exactly that in the deck name). It's still slow and vulnerable, though. Cool when it works, but definitely one of the decks where you can feel the setup cost, which is essentially the theme of these bottom 3 decks.
B-TIER
7. Might of the Legion (RW / Boros / 🔴⚪)
Maybe the most perfectly average deck among all of the starter decks? Cast a bunch of bodies, add more bodies to the board, then cast something like Heroic Reinforcements and suddenly the collection of 1/1 idiots your opponent has been ignoring is lethal. Solid token aggro. Nothing particularly strong, but when you figure out that you can throw 8 creatures at the opponent just like that, it's not particularly hard to understand either.
6. Cat Attack (GW / Selesnya / 🟢⚪)
Make cats. Make more cats. Make all the cats bigger. Eventually attack with an amount of cats that becomes socially unacceptable. Might of the Legion, but cats, basically. Just ranking it higher than MotL because it seemed to ramp a bit more smoothly and had a bit better setup cards. Also because cats.
5. Learn from the Land (UG / Simic / 🔵🟢)
I played a Forest in one game and it set off a handful of triggers. That was fun. When it gets going, it really gets going. Early turns are pretty standard, then as long as you've got the right cards, the ramp up of this deck could be an avalanche. It isn't as slow to setup as the bottom 3 decks I mentioned at the top. But some of the faster, cleaner decks won't politely wait for it to get going either.
A-TIER
4. Path of Power (RG / Gruul / 🔴🟢)
Really strong, big, proactive deck. Maybe the most beginner friendly starter in terms of how straightforward you need to play it? Make mana, play things that are bigger than whatever the other player is doing, then start smashing. Curiously, had more problems with the cat deck than any other deck when I was playing this. Maybe because of the cat deck's ability to throw away blockers against my big bodies long enough to outlast me when playing PoP.
3. Reckless Raid (BR / Rakdos / ⚫🔴)
Okay, so if PoP isn't the most beginner friendly deck, then maybe this is. Just attack bro. I'm just calling PoP the more beginner friendly one because with this deck, you're still thinking of the Raid abilities and balancing out their rewards against the decision to attack when maybe it's not that favorable to you at the moment. Raid rewards you for having attacked that turn, so even attacks that aren't amazing on raw combat math can unlock Perforating Artist, Strongbox Raider, Goblin Boarders, etc.
S-TIER
2. Arcane Aerialists (WU / Azorius / ⚪🔵)
The first of the two most disgusting starter decks here. The game plan is super straightforward: clog up the ground, keep sending evasive creatures over the top, and eventually your random little fliers stop being random little fliers because Empyrean Eagle and the rest of the deck start juicing everything. Very consistent, very easy to pilot, and flying is apparently a hell of a drug.
1. Vampiric Hunger (WB / Orzhov / ⚪⚫)
The safest, least frustrating, and also most fun, powerful deck overall. Seemingly harmless cards like Healer's Hawk and Hinterland Sanctifier start feeding Ajani's Pridemate and by Turn 3 suddenly your board gets way out of hand - and that isn't a rare occurrence with this deck. But in case Plan A doesn't immediately snowball, this also has actual removal and enough grind to survive until its setup comes online. Probably the most “I don't hate any matchup” deck of the ten.