Thanks! For the tokens, I have the characters as separate, but I expect anyone using their existing epic-scale mini collections probably has their infantry characters multi-based. Either option should work fine, and I would leave it to personal preference.
The number of models per base and exact base sizes for different unit types are general recommendations, not hard and fast rules. So, feel free to use infantry on 40mm strips instead of squares/rounds, if that's what you prefer and your fellow players are fine with.