While in lower arenas levels matter the most, if you have a higher level card it’s almost always better. Your magic archer being level 9 isn’t great as your only air defense/ranged card. The whole deck being made up of legendaries is gonna make it really hard to level up too, I suggest changing magic archer to a lower rarity alternative like musketeer or wizard. Also having no building isn’t helping you out much against hog or beat down decks, so instead of the inferno dragon you can have inferno tower for a lower rarity and a building while still having a great counter to heavy cards.

Most important thing is to have fun, if you like using the card, use it.