I will assume the firearms are loaded.
This is an accident, for which you may well be held liable, waiting to happen. You have just announced they have disengaged safeties on purpose, and announced it all over the internet for any lawyer's assistant to find.
Being able to disengage or engage the safety of any weapon you plan to use in a self defense situation is fairly important business. It just takes some practice and muscle memory. This can be done with dry fire drills pretty effectively as well as range time. You can minimize some of this by using handguns designed to be used without a deliberate and separate safety disengagement. Glocks and DA revolvers have been mentioned. There are some others as well.
"A Liberal is someone who doesn't care what you do, as long as it's mandatory". - Charles Krauthammer