Graham 
A top-heavy mana curve may be the problem, but weak ramp, missed land drops, color requirements, or empty early turns can create the same symptoms. Use this workflow to find the actual bottleneck before cutting every expensive spell.
A deck builder manages the list; a mana curve analyzer diagnoses how its costs and casting demands are distributed. Here is how to use both in one practical tuning loop.
Combo redundancy is not simply adding more combos or tutors. It is the deliberate use of shared pieces, valid substitutes, and overlapping lines that give a deck more ways to assemble a win without wasting slots.