Problem is, there is not 1 or 2 or 3 act, this not a Bioware game where every part of their games is divided in acts or chapters and everyone of these have a particular story
Its not an argument, its a point of view, whether this DLC was worth the money is totally subjective
Fallout Tactics is canon, what is not canon and a controversy is "The Burned Game"
Acts 1, 2, and 3 aren't solely for video games, nor are they only for certain types of games.
Any good story has 3 acts. Act 1 shows your protagonist living his normal life, be it living with his family in a village or going to a 9-5 job, and usually ends up with something going wrong, sometimes referred to as "the big question". Will the character defeat the dragon? Will the character hunt down the man who robbed his home? Something along that line.
Act 2 involves the character gathering what he needs to answer "the big question" be it tools, companions, information, etc... That's where a lot of gameplay in games comes from.
Act 3 is the climix. The character answers the big question, all issues get resolved, and sometimes you see the after math of the stories events.
Bioware didn't invent the 3 act formula, it's been around for ever. It's in movies, books, television shows, stories told around a campfire, etc... Just because the game doesn't say "THIS IS THE FIRST ACT" doesn't mean it doesn't have an act. For example, Fallout 3's first act was the tutorial. You see yourself grow up in a vault, mingling with the people he has known his entire life, and then leading up to the big question. Will the lone wanderer find his dad? Act 2 is where the gameplay is, wandering the dessert, finding information, growing stronger, etc... And act 3 was originally taking the purifier before broken steel.