Okay,
You can use timers/timed events if you do not want to use delays. A timer will allow you to continue executing code while it ticks down to 0 and fires away.
You should avoid delays in situations that are dynamic. That means, if you are not 100% certain that the timing of the delay is going to be the same every instance, then you may want to use a timer instead, or your code can lock up. (As in, a vital function will have to WAIT until the delay is complete.)
Your colleagues may be informing you with regards to their personal workflow. Keep in mind that there is no ONE way to do anything in Unreal. And as long as you are logical, you’ll be fine.
EDIT: It’s also VERY good you are asking questions. Don’t let anyone make you feel uncomfortable for not already knowing what they may know. There’s too much of that here.