In practice, modern gaming usage is that “tactics” is a proper subset of “strategy”.
Yeah that seems to be the case. But what do we call real strategy games then? Slow Tactics?
The deckbuilding part is where you plan your strategy, which you then have to execute in real time.
Sure, that's fine, but it's the execution part which bothers me from a strategic viewpoint—maybe the video was very unrepresentative but I didn't see anything strategic in it, just a sequence of pre-planed tactics. The problem with that is…
“No battle plan survives contact with the enemy.”—Helmuth von Moltke
or more poetically
"The best laid schemes o’ Mice an’ Men Gang aft agley"—Robert Burns
In older RTS, the 'S' part initially involves deciding whether to favor early attack or defense, when to start ship building, will we spend on air force or air defense, and so on—generally decisions re resource acquisition and spending.
After enemy contact beyond scout level, the 'S' part changes to involve assessing enemy action and how to counter it or take advantage of it. Gameplay becomes fluid and tactics come more into play as opponents seek to capitalize on strategic omissions.
Tactics - the methods you use to win a battle
Strategy - the battles you're going to fight to win a war
RTS games are often more about tactics than strategy.
Tactics: ; How to;
Strategy: What to.
RTS can absolutely be played as mostly tactical—ref the infamous 5-minute rushes in C&C multi or the APM play in Starcraft. But that's a different genre, not RTS—it's the Get my name higher on Leaderboard genre
And it's fine, but please call it what it is—RTT—so we still have a name to distinguish games with strategy once the real-time part of the game has commenced.
Blitz Chess gets a different name.