We have seen things like that happen, such as literally anytime a movie goes back to do reshoots.
While this might feel like an overreaction, the fact is that overreaction is exactly what Todd McFarlane is apparently trying to avoid.
While that flexibility would be perfectly normal on the set, from the outside looking in, it might appear to be a bigger issue than it actually is.
Spawn isn’t going to have the sort of budget that your traditional big-screen comic book movie has these days, which means the production is likely going to need to be flexible in order to stay within the confines of the money they have.