Here Is a perfect example why topping Evergreen trees is never recommended. 
Once you cut the stock, multiple limbs grow straight up to recreate tops. 
This causes multiple tops. 
In time, they will start losing space for each other to share and breaking off causing damage to structures, hazards to humans / animals. By cutting them is creating an unhealthy top; basically causing a wound and exposing them, water saturation causes decay and rot, then breakage when the tops grow and get heavy.