Shadowverse: Starforged Legends

I tend to use fewer Frog Riders than Mouse Riders. In decks focused on Ash creatures, they're not great, but in a standard aggro deck, they provide infinite value. You can flood the board and keep up with the mana curve like any other aggro deck, but you also have a Frog Rider that can deal significant damage under the radar.
And yes, I didn't have any problems against Ash decks. Sylvan decks can easily beat them, and Blood decks simply overwhelm them. I don't know why you think it's difficult for Sylvan to play against Ash. It's more likely that you're just struggling against aggro decks in general, but the Frog Rider itself isn't the problem.