I wouldn't recommend 2 as an entry to the series as it's the toughest and grindiest of the lot. 4 is the perfect starting point, and then you can go back if you want to see the rest. It'll be tough to go back though, due to all the quality of life improvements the later games provide.
If you're a masochist play them all in release order.
Honestly, EOII is not that bad.
I mean, it may feel "grindier" than III or IV during the main game, but don't forget/discount that you can beat the post-game stratum and boss at the standard level cap of 70 if you farm up good gear and have a good party (mainly that means having a paladin, which you can get through a bunch of the game without until then). Now consider how much more tons of grinding there is in III and IV to do postgame stuff, level cap quests, stat book farming, formaldahyde/conditional farming.
Also, subclassing...yeah it's fun and I like it, but the straightforwardness of party member roles is something that EOII does really well--frankly, I appreciate the (relative) simplicity of II after all the
hours I spent burning my brain playing with builds in EOIII (and to a lesser extent EOIV).
After playing III and IV, I'd still recommend II, as much for what it does well as for what it doesn't do at all.
Disclaimer/perspective: EOII was my intro to the series after EOIII was already out. I played III second after I tried and failed to get into EOI (I got EOU instead to play enhanced EOI) but I still haven't beaten Abyssal God (my party is getting there though). Got started on IV about a month ago, finished main game last week, retired my starting party at level 99, grinded them back up to 80s, now grinding a new party up to 99 to retire to get some new classes to try on postgame stuff.
I'm not really sold on that nightseeker in front over a sniper in back, but I don't know shit about this game so maybe it will work out? The guy looks cool at least, haha.
I started my EOIV game with F/N/D | R/M (that's Fortress, Nightseeker, Dancer, Runemaster, Medic) and I'm still using the same party in the post-game content. It was a bit rough early on, so I grinded a bit extra and didn't have too much trouble with the 20-40 level range except for the second main boss. Once I got to 40 the game turned into maxiumum easy mode thanks to Nightseeker's Poison Throw which is so powerful it will even clear encounters in the post-game (hardest) dungeon in 1 or 2 turns. I had no idea it was as powerful as it is, haha.
Nightseekers are a good pick for your starting party and are super strong past level 40. They're also fine in the front row because all their damage skills are from blade weapons so you'll want them on the front row for that. However, they're squishy, and doubly so because you'll want them to dual wield weapons so they lose a piece of armor to do that so you'll either want to invest in Shadow Cloak for them or make sure you have your Fortress to use Guard skills to protect them. (I skipped Cloak since I have a Fortress.)
If you want to get a little more detailed with your party management you can start battles with your Nightseeker in the back row to use Throw skills and leave them there until it's time to move in for the kill with their weaponskills like Shadow Bite or Swift Edge. In EOIV, unlike in 1-3, changing positions in battle doesn't take your character's turn. This can get tedious but it's a feature you can really take advantage of.