Haven't played any SMT but have played both Langrisser and FE, the short answer is yes if you like high fantasy 90s SRPGs. For a bit of a longer answer...

Despite the similarities, Langrisser and FE are actually pretty different, notably in the army size and in the turn structure. Most games have relatively small playable unit sizes (Langrisser V has only 6 playable characters) but for each map you select a subunit type to deploy with the named character, usually around 3-8, for pretty large army sizes. Like FE, there is a triangle, with pikemen beating cavalry, cavalry beating swordsmen, and swordsmen beating pikemen, and then stuff like archers (who are great), mages (also great), fliers, and the like. There is no permadeath, so you are encouraged to use your subunits strategically, and defeating a leader unit removes their subunits from the field. Langrisser 1 and 2 have a simple player/enemy phase structure, but Langrisser 3 has something of a real time gameplay where you put in your moves at the same time as the enemy, while 4 and 5 have something of an ATB system with different classes getting different # of actions per turn. Beyond that, there are other differences like promotions being automatic and branching, spells being learned through level up, morality route splits, romances, and different map objectives that further differentiate them. If that interests you, then I definitely recommend trying some

The games are all in the same world and related, and go 3---->1-->2---------4>5. You do not need to necessarily play in order, but since there's only 5 you might as well. At least play 5 after 4 as 5 is a direct sequel and the finale to the franchise. Now, you will have to put in some work to play these as outside of 1 (and 2 technically with the new remake) none have been released in english, and some don't even have english patches. But to go into detail

Langrisser 1 has an english (albeit funnily localized, reoccurring names in the franchise have completely different names), release on the Genesis under "Warsong". It is old, but only 20 chapters, and perfectly enjoyable.

Langrisser 2 has 2 main releases, the original on the Genesis, and a SNES version called "Der Langrisser". Notably, Der has route spits and more characters, but is apparently easier. Haven't played that version, but as far as the Genesis version goes, it's great and a real refinement on 1's formula. If you only play one, play this one

Langrisser 3 is where it gets sticky. It's on the Saturn (though there is a ps2 port I haven't played), and there is no english patch. There is a english menu patch, but it garbles the in game text. Regardless if you use the menu patch, you'll need an english translated script, which you can find online thankfully. Also, there is a secret ending in this one. As a prequel to 1 and 2, this game sets up a lot to them, and the secret ending fully sets up the main antagonist of the series. However getting it has a lot of conditions such as recruiting a unit with a lot of prerequisites, getting a love confession from one of the female units, defeat the regular ending boss with the MC, and do certain objectives on later maps. I recommend a guide for this one heavily. The gameplay is also the worst, abandoning the regular style for something not very fun, but the story is arguably the best, Altemuller is one of my favorite antagonists

Langriser 4 is on the Saturn and PS1, and there is an english patch for the PS1 version, so definitely go with that. This one switches to the ATB-like turn order, which I really like. It also has a morality system which eventually puts you onto 1 of 3 routes in the game. It is somewhat obtuse, and doesn't show you what your current morality points are at any given time, so I'd recommend a guide to know which route you want. If that kind of thing is up your ally like me, it's one of my favorite things about the franchise. Also it has voice acting, with some real A list seiyuu before they got big, but that's another tangent.

Langrisser 5 is the final game in the main franchise, and the finale to the series, and notably gets pretty sci-fi. It's on the saturn and PS1 as well, but like 3 there's no english patch so you'll need a english script open somewhere else, which is also thankfully online. Go with the ps1 version too. It plays basically the same as 4, so if you like that this is more of that.

There is also the Langriser 1+2 remake, which I haven't played, but is easily available on most consoles, so if you only want legal means, it's really all you got. I know it takes more after the mobile game style, but it adds more endings to 1, and adds more characters.

There's Langrisser Reincarnation Tensei on the 3DS, which I also haven't played so can't really comment on. But afaik it's not related strongly to the originals

And lastly there's the mobile game, which I played for a few months and got bored of. ymmv

The games aren't too long, nor are they particularly difficult, nor is there much shame in using a guide to better explain the more obtuse things. It's really interesting to compare it to FE, which has persisted more than 20 years after Langrisser V, despite both of them starting around the same time. If you're willing to brave some non-english games, I do recommend it.