Okay putting ASIDE that none of you know what the word "strategic" means, I can totally see where FL is coming from with the OP - XIII is far from the first to split your party up for an extended period. IX did it of course, but so did VI and, perhaps the most of any FF, IV. I'm not entirely sure how much it factors into a game as such though, it's going to heavily depend on the characters in question, both in terms of utility and in terms of how much you like them. I love Sazh and Vanille both, so having a whole chapter with just them is fine with me. Lightning decking Snow repeatedly is hilarious and I'm always okay with them bickering. OTOH, I adore Freya and like Steiner a great deal, so taking them away from me for extended periods was annoying as hell. And I can't believe anyone would think a party that didn't include Palom and Porom is viable, let alone required.

But JRPGs have an inherent structure that has been set in stone since they first emerged, and it has never changed much; you go on a long, linear adventure for the first 50 hours, then the game opens up and you get access to bonus dungeons, can pursue sidequests, and collect the best gear, before you head to the final dungeon and finish up. There are certainly exceptions, but more or less the only variable is the number of hours to hit endgame. Some games it's 20, some it's 70+, most are in between.

This is inherently limiting compared to many games in the western canon, like the TES series, where you can break the entire world in half at level 1 and kill a god with a lockpick if you take enough drugs. A JRPG has pretty good knowledge about what level you'll be when you get to, say, Icicle Inn, and what equipment and spells you'll have. The game is tailored to those expectations. A game like Gothic would just let you wander across Icicle Inn and get smurfing murdered by Elena so hard your game uninstalls itself. They just don't operate on the same assumptions. And that's okay! It's okay to have different approaches and give the player different things, I enjoy both subgenres a huge amount personally. But it does mean you kind of have to know what you're getting into, and that there are certain conventions which most games won't break out of. I mean, as much variation as there is between IX and XIII in battle systems, they're both still vastly closer to each other and all other single-player FFs than they are to TES, or to Baldur's Gate, etc..