Interesting. I have had to deal with two episodes of cut wrists. The first (an accident) was with cut tendons, but not severed main artery. There seemed to be minimal blood loss, because of shock and fast application of first aid. Result: an immediate operation to fix the tendons.
The second was caused by jagged metal (a broken coke can) Blood everywhere, especially on another guy's coat. It happened in a London street. Result: Police (at first) jumping to conclusions. Young woman hospitalized.
Yes. You can cut several tendons without cutting a big artery. The are only 2 major arteries in the forearm. If you don't hit them you will not have blood
everywhere, if you do you
will have blood everywhere. Veins can also bleed a lot, but not near as much as an artery. Veins are just dripping.
It also depends on HOW you cut the artery. A transverse cut is less dangerous because effective vasoconstriction (due to shock) can occur. If you make a long longitudinal cut the vasoconstriction will not be effective (=life-threatening bleeding). Cutting off the forearm transversely (so the hand is separated from the forearm) is
less dangerous than making a longitudinal cut through 1 of the 2 big arteries. Because of what I explained about effective vasoconstriction.