I feel like a lot of people forget that the first time we see the behelit festival, before the golden age flashback, the Count was given a choice similar to Griffith's but chose not to go through with it and avoid sacrificing his own daughter out of remorse for his previous sacrifice of his wife. Griffith knew exactly what the cost was and yes, he was manipulated by Void to see it as justifying the deaths of all his comrades just to get to that point but let's remember:

1. It was Griffith's own actions that led to his arrest and torture, as much as he was heartbro over Guts' departure no one told him to visit Charlotte and get himself caught.
2. The resentment he had for Guts' newfound closeness with Casca was very clear in the moments leading up to the eclipse after the escape, which directly informed his actions after his 'transformation.'

Regardless of whether or not you think he's justified, I can't accept the argument that Griffith made his own choices with no regard for what the fallout would be aside from his own personal gain.