I'm luckily enough to work on a small team like the one you described, and yeah - our trello board isn't fully fleshed out. We can put vague descriptions of what needs to be done and the team gets it done.

I think SMART goals are one of those rare times where an HR course writer unintentionally hit on something that some people need to hear. There's a junior engineer on my team whose goal was just, "I want to get better at infosec" - not measurable, time boxed, etc. by trying to at least hit one or two of the guidelines, they were able to flesh out this goal into things like "I want to attend a major security conference this year" and "I will study for, and achieve my Security+ cert".

It worked for them - and helped them clarify their broad nebulous goal into smaller specific and achievable goals - but obviously like all business/hr things SMART goals aren't for everyone.

While it's all fine and good to just say "hire the right people", that's a gross oversimplification. Those people became "right" through time and dedication, which led to experience. Not every employee will be a "right person" and none of them started out as one. Also consider that not every manager is a "right person", so making SMART goals protects you from their managerial inadequacy.

SMART lays out how to both set and receive tasks, goals, assignments, etc., that are clearly defined. A goal lacking in one or more of these elements is what is commonly referred to as a "shitty goal". Why? I'll lay it out using the acronym from the perspective of an employee, plus an example for each of what can happen when that information is missing.

Specific: what does my boss actually want from me?
Converse - I completed the wrong task.

Measurable: how do I prove I did the task and how well it was done?
Converse - I did great work but can't prove to the client how great it is.

Achievable: can the task actually be done with the time, knowledge, and resources available?
Converse - I agreed to complete a task which turned out to be impossible given our resources.

Relevant: how does the task relate to the job/project/etc?
Converse - I completed an unnecessary task. Now I have to work even more to undo it and complete what actually does need to be done.

Time: when does this need to be done by?
Converse - I completed the task after it was needed, putting the project behind.

If you're missing any of those parameters, you're either not giving your people enough information or they aren't asking enough questions. I'd love to hear how work can be consistently done well if any of that is missing.

Those "right people" you mentioned are likely already incorporating these elements into communications with you. Dare say that makes them... SMARTer than you? Heyo!

Even with what you've described, smart can still apply. The goal that's set would be a specific, desired outcome, the who, what, where, when, and why of how you get there, is up to the best judgement of the team. It's measurable in the way of having some way to determine that the specific goal was achieved.

That's S and M, for A, achievable, I'm sure the team would let you know if a goal is not able to be reached. If they didn't think it can be done, they would not waste time trying.

Relevant is mostly irrelevant for the workers, that's more whether management decides it is relevant to the companies goals.

Time-based ... This is the part I'd have the most trouble with. It takes however long it takes. As long as nobody is dragging their ass, it shouldn't take any longer than it needs to, and putting a time constraint on it just puts undue pressure on the team for no good reason. As long as progress is steady and things are getting done, then time shouldn't really matter all that much.