These folks are professionals, they train day in day out, they plan every raid.
LOLOLOLOLOLOLOLOL......... LOLOLOLOLOLOLOLOLOL....
For starters much of what a SWAT style team does is rapid response. That in itself denies much planning.... second, I wouldn't count on even the largest SWAT team in the country being trained real well.... they might be, but they might not be....
Throw into the mix that many departments don't use actual SWAT teams to do no knock warrants, and you sometimes have Joe cop kicking in doors with no pre planning aside from "alright, I'm kicking in the door now".
Minneapolis, for instance, has a TERRIBLE record for mistaken houses being raided....
even if you do take a few of them down with you, you will not win the fight.
Tell that to the INNOCENT Vietnamese guy who defended his whole family and held off the entire Mpls PD high risk entry team for long enough for his wife to get a call in to 911, get patched through, and explain the situation before the officers hit anyone in the house with their very numerous rounds..... he fired three times and hit 2 officers....
He used a 12 ga pump shotgun IIRC.... they used, well, by the shot count, probably about everything they had available to them....
And this is not the only case.... It DOES happen....
(for the record- The entry team was publicly honored for their bravery and service under fire about a year later..... *geesh*)
EDIT- here's an article about it
http://wcco.com/iteam/iteam.police.raid.2.652690.html
As to planning from the SWAT team-
[editorial- they arrest the perp]....Then they decide to go after guns his girlfriend has told them about.
Several hours later, VOTF officers meet with Hennepin County Judge Herb Lefler at his home. They convince him it is urgent to move fast before someone ditches the guns since Brown is now behind bars.
The I-TEAM has looked into what could have prevented the mistaken raid. It's standard in cases like this to do surveillance outside a house and check for any police calls to the address.
Investigators also could have run a simple property search online and learned that the Khang family owned the house on Logan Avenue since moving there four years ago.
So far, the I-TEAM has found no evidence that any of those steps were taken on the Logan Avenue house to confirm the information provided by Brown's girlfriend
Now, I'm no cop basher, in fact my own well loved Uncle was a member of the FBI violent offenders fugitive task force some years ago...... But I am a realist.... and it really does happen... more than you or I probably know about...