Really? Regardless of Horridon tuning, 100 attempts for a boss #2 normal mode clear is WAY too high. Assume a 'normal mode'/casual group raids 2-3 times/week for a total of 6-9 hours. Let's say that time is spent only on Horridon. 30min of trash (x3) and 30 min worth of breaks leaves 5-8 hours of attempts. If the average attempt takes 10 minutes (5 fighting / 5 wiping/running/rebuffing), the average guild might have 30-50 attempts/week. 100 attempts would mean 2 to 4 weeks worth of pulls on Horridon and nothing else - the second boss of the instance.
There is no way that a normal mode fight is intended to take the average 10man 16/16N guild 100 attempts to clear.