Actually, no. There was a time, but Tempo and Midrange are sortof parallels that catch everything not covered by the 4 older archetypes.
What Midrange decks do, as force of habit is play to the highest EV (expected value) of their cards, (not to be conflated with “goodstuff”, which is just a type of deck under Midrange’s umbrella.). The hallmark of a Midrange deck is to play only cards with super high utility, regardless of how much support the deck has for them. A Midrange Argeon deck, for example- might play Blades and Trinity Oaths over Bonds and Ironcliffes- and Elyx to layer with the blades. The shell of bomb 2 and 3 drops remains relatively un-molested, but that’s because Midrange decks want to be live at every stage of the game. A card you probably wouldn’t play much in a midrange deck would be Slo. An excellent card with a low opportunity cost, but a low EV as well. Windblade Adept can pressure or make good trades, Lions give you options, and Silverguard Knight can mess with your opponent’s positioning and create strong trades. But Slo is primarily played for it’s Immolation combo- where a midrange deck may prefer Maw or Bloodtear for the same trick to give it scaling.
A Tempo deck, on the otherhand is all about resource efficiency- making sure you get the best of it, and your opponent gets the worst of it. Here, you want to be playing lots of “beatsticks”- generously costed bodies relative to their cost, as opposed to cards with a high baseline of EV. A tempo deck will likely eschew most high-drops in favor of inexpensive disruption. In this deck, Slo is the absolute best card- because it develops without using mana- making it capable of taking a spring and ramping- or more importantly, it makes movement tougher for your opponent and allows you to force them to make answers. Tempo Argeon, for example, plays Arclyte Sentinel- because it often allows you to trade face, or a small minion, and then finish off your opponent’s threat with the sentinel- further developing your board while cheaply putting your opponent behind.
I like to think of archetypes as being on an axis- where they are at odds with another archetype. I learned to think about it this way from a book written by Patrick Chapin called “Next Level Magic”. His model isn’t exactly the same, but the ideas are coherent.
The “Fair” Axis- Aggro vs. Control:
The deckbuilding strain to play threats vs. utilities. Typically, trying to have lots of both tends to make a deck inconsistent or ineffective.
The “Unfair” Axis- Ramp vs. Combo:
Deckbuilding strain related to building a sick combo that wins the game, or playing something ahead of schedule to the same effect. Historically, in most CCGs, these are the decks that get “banned out”, or in the case of Digital CCGs, get errata’d the most, because they exploit blemishes in the game design.
The “Switch” Axis- Midrange vs. Tempo:
These used to be collectively called “Aggro-Control”, since the decks play “fair”, but unlike Aggro and Control, they have a habit of not punishing Unfair decks for playing unfair. The operative strain here is what manner of “gear shifting” occurs over the game. A tempo deck can quickly shift into playing like a combo deck, where a Midrange deck can often easily shift into playing like a Control deck. A tempo deck is built to include surprise kills, or to put such insane pressure on the opponent when you get far enough ahead, even answering your threats leaves you in danger. Where a midrange deck would prefer tools that make it resilient as the games moves through it’s phases- meaning that the all-in tempo plays are just no bueno.
And they’re certifiably okay in an aggro deck with lots of reach.