Golgari Grave-Troll + Golgari Thug Busted in 60-card formats, dredge plays more like I think the designers thought it would in the diluted space of 99-card Commander decks
Path to Exile is the optimal removal for the deck (especially since we can sometimes eliminate the downside of giving our opponent a land with Leonin Arbiter), but Declaration in Stone is a fine budget replacement with some upside against token decks since it exiles all copies of a creature
This could be a classic on the level of All Sun's Dawn
Both Violent Outburst and Shardless Agent are the backbone of every Cascade deck being played in Modern nowadays, and currently there are two tier 1 decks (Living End, Crashing Footfalls) cascading into powerful spells to win the game
The other cards are sweet, but I particularly like that The Spear of Leonidas has three choices when you attack with it, including summoning Phobos, a legendary 3/2 red Horse creature token