My friend and I built around with some redstone stuff and got into building traps.

So we built a hole, with a pressure plate and 8 dispensers full of arrows around and with a bit of redstone all of them shoot when u stand on the pressure plate. But here comes the problem:

It doesn't matter how many dispensers there are or if I attach a redstone clock to the wires, all of the arrows together deal just 1.5 hearts of damage and to be more precise one arrow hits and the other ones bounce off of me and I can collect them from the ground.

After seeing that this problem was known for PE and fixed there, that if you are to close to a dispenser it doesn't work, I figured it might go with distance (rebuild in screenshots) so i tested it to a range of 3 blocks and even then I get hit down to 8.5 hearts.

I suppose this can't be a "feature" and here I am. I hope you can help and thanks for reading.
Happy Easter btw