The only thing you really need to add would be N or a Giratina DRX to the list. Giratina DRXs shred attack is better than Hydreigons because at least you’re ohkoing Sigilyph. You’ll always have to attack twice to knock out a safeguarder with Hydreigon.
Giratina/Vileplume in expanded is fine the way it is in standard for the most part. I wouldn’t think too much about it.