I don't know if this'll help anyone so don't flame me(!) but I've taken the number of tiles (normal and minimised) needed to evolve and worked out the minimum and maximum number of moves it'd take to mega evolve. You can then compare the normal vs. minimised number of combos to evolve.
| Mega | # icons | Min combos to evolve | Max combos to evolve | Minimized # icons | Minimized min combos to evolve | Minimized max combos to evolve |
|---|---|---|---|---|---|---|
| Aerodactyl | 23 | 5-5-5-5-3 (5x) | 3-3-3-3-3-3-3-3 (8x) | 16 | 5-5-5-3 (4x); 3-3-3-3-3-3 (6x) | |
| Altaria | 22 | 5-5-5-5-3 (5x) | 3-3-3-3-3-3-3-3 (8x) | 16 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) |
| Ampharos | 24 | 5-5-5-5-4 (5x) | 3-3-3-3-3-3-3-3 (8x) | 17 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) |
| Audino | 12 | 5-5-3 (3x); 3-3-3-3 (4x) | 9 | 5-4 (2x); 3-3-3 (3x) | ||
| Banette | 27 | 5-5-5-5-5-3 (6x) | 3-3-3-3-3-3-3-3-3 (9x) | 19 | 5-5-5-4 (4x) | 3-3-3-3-3-3-3 (7x) |
| Blastoise | 19 | 5-5-5-4 (4x) | 3-3-3-3-3-3-3 (7x) | 15 | 5-5-5 (3x) | 3-3-3-3-3 (5x) |
| Gengar | 11 | 5-5-3 (3x) | 3-3-3-3 (4x) | 10 | 5-5 (2x) | 3-3-3-3 (4x) |
| Glalie | 19 | 5-5-5-4 (4x) | 3-3-3-3-3-3-3 (7) | 13 | 5-5-3 (3x) | 3-3-3-3-3 (5x) |
| Kangaskhan | 16 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) | 8 | 5-3 (2x); 3-3-3 (3x) | |
| Lopunny | 16 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) | 8 | 5-3 (2x) | 3-3-3 (3x) |
| Lucario | 14 | 5-5-5 (3x) | 3-3-3-3-3 (5x) | 10 | 5-5 (2x) | 3-3-3-3 (x4) |
| Mawile | 21 | 5-5-5-5-3 (5x) | 3-3-3-3-3-3-3 (7x) | 14 | 5-5-4 (3x) | 3-3-3-3-3 (5x) |
| Mewtwo Y | 23 | 5-5-5-5-3 (5x) | 3-3-3-3-3-3-3-3 (8x) | 18 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) |
| Sableye | 22 | 5-5-5-5-3 (5x) | 3-3-3-3-3-3-3-3 (8x) | 14 | 5-5-4 (3x) | 3-3-3-3-3 (5x) |
| Slowbro | 18 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) | 16 | 5-5-5-3 (4x) | 3-3-3-3-3-3 (6x) |
| Venusaur | 15 | 5-5-5 (3x) | 3-3-3-3-3 (5x) | 12 | 5-5-3 (3x) | 3-3-3-3 (4x) |
Any errors, let me know.