Harmony - Troop Symmetry

Reducing movement speed will also negatively affect skills that depend on the number of tiles traversed: agility, charge, and cavalier charge. When balancing the mod, you need to consider that these abilities have become slightly less valuable.

All of these abilities can be adjusted in the same file, GameMechanics\RPGStats\DefaultStats.

In my mod, for example, agility provides twice the bonus (+4 equivalent), charge remains unchanged in terms of formal modifications (the actual bonus has increased due to the increased importance of defense and because it now provides the maximum bonus after 5 tiles). Finally, cavalier charge was increased from 5% to 10% per tile, transforming it from a minor background ability into one of the strongest and most distinctive.

In your case, to avoid strengthening the original abilities, I would increase agility to only +3, the cavalry bonus to +10%, and there is no need to change the lizard charge, as it is the same whether it is 8 or 5-6.

Regarding movement speed, I can suggest another alternative: based on Heroes 3, you can convert speeds using the formula 75% (of what they were in Heroes 3 for these creatures), rounded down. This is a practically exact imitation. However, I would then only base it on upgrades, as the base values in Heroes 3 are significantly lower in terms of speed - and similar zombies in Heroes 5 would crawl at 2, which is historically accurate in itself, but initiative is already low.