Is the whole game going to be like this? (Vesperia)

I picked up Vesperia (PS4 version) to take a break from Arise. I keep hearing that Arise is more difficult than the other games, but I've only played Phantasia before these (half of it, and button-mashed my way through) so I can't confirm myself. I usually like easier games but I've had little issue with Arise on Normal. (I'm in the 5th realm in Arise, if that says anything.)

It took me like 5 tries to get through the Zagi fight at the beginning, used up all my Apple Gels and both character's TP to do so. That was the least fun I've had in a battle in this series! In the second phase there was no break in the boss' combo so there was no skill- or strategy-based way to defeat this boss. Yuri is supposedly locked on to the boss, and is right next to it, but will swing at the open air when he feels like it. And this is after figuring out that the L stick has to be exactly neutral to use the Arte (which is great with a boss you have to chase around).

I really want to like this game, so I'm wondering if the whole thing is going to be a clunky mess like this, or if things will balance out with more characters and abilities. Will setting the difficult to Easy have a meaningful effect or are the issues with battling impossible to avoid?

EDIT: Thanks guys for the helpful comments! Going forward it was clear that something weird was going on during that battle, as immediately after I stopped having issues with targeting/defending/using artes. Those of you who dismissed my post as a "skill issue", I'm going to ignore those comments.