Depends.
The Answer: In one instance, Ymir is better than Radd because let's face it, if you're gonna keep 14 units alive for each Gaiden character up until Ymir, 4 of the 14 being Horce, Athena Etzel and Marth, I'a gonna guess that Radd isn't going to be among the other 11; you'll jsut kill him and get it over with as his level sucks.
The simple version: Because Ymir will actually be alive by that chapter.
The Answer 2.0: On the other hand, if you train him smartly by letting big units hit the Horsemen in his recruiting chapter (Jaigen, Roger, Drag and Shiida + Wing L. come to mind) then Radd can g in for the kill and will Level up pretty damn fast. IF, and only IF you can level him, he's useful. Honestly, I've never used him as a Myrmidon aside from killing priests, mages and the occasinal arena. Anything with low DEF, basically. Endgame, if you 20/20 him, he's damn good. Generally ahs a bit more STR than Navarre though significantly less SKL.
She's slow off the start compared to enemy units. I mean, shit, In normal mode she can fall pretty fast. Well, if you're dumb...but still takes a fair bit of damage.
Personally, my team consists of Speed units + Gordin. You can't deny that fast units like Ogma and Navarre come in handy when facing pirates and shit and compared to toher archers, Godin just seems to have slightly more defence when he's hit. The only real risk with him is his speed because he can get doubled fairly early. Mages are also useful because for once, the lack of resistance can come into play in our favor. Merric is awesomeness with Excalibur. Failing that you don't wanna use it, get a Blizzard from the online shop. But honestly, if you're getting the Hammmern alter, use the sacred tomes. Everytime I've played I've always wound up with like, 5/7 Hammern uses left and a bit over 30k in gold left even with forging. (Alot of arena abuse for my teams...) But seriously, use the staff.
H5 is great for Hardin in my opinion. His spot in the 'High' is well-earned no amtter the rout he takes. I don't take advantage of his high lv in Ch5. Instead, I make him a healer if I already avhe other units that are decent close-range fighters. He already comes with 1 Res anyway. And if he doesnt gain any Mag or only about 2 Mag by lv20, then just change him back to a Melee class after promote and he's got a fair amout of magic resistance. Give him a Forged weapon. Steel Sword with a bit of added Mt is useful as fuck in that case and his resistance on yop of that makes him a killer against the magic users. He'll still take some damage but less healing in the long-run.
I will however say that Roger should be a bit lower. The only thing he can brag about is his Luck growth which is cut in half as we all know. I personally use Draug as a Pirate because of the speed he has as one. Can't really say the same for Roger unless you want to reclass him later, though as what, I donno...He just...sucks...I mean, somewhat good Def but poor Skl and Str off the start. And on the subject of Knights, how Dolph is higher than Navarre is beyond me. Navarre is useful when you get him, or you can just give his killer to Ogma...eitherway but he's good for the hits. Dolph gets doubled and needs some tending to. Well, so does everyone but one's a bigger liability. I mean, Dolph joins at Lv4 during Ch12, and Navarre is at Lv3 during Ch2. Hmmm...I wonder which one will have had time to grow by Ch12? Honestly, if the only reason you wouldn't be using Navarre is if you've done some good shit with Ogma. Failing that, I'm pretty sure by Ch12 Navarre is going to be AT LEAST lv10. AT LEAST. I mean, in my game he was...but that's just me...I use Gordin too...I've only ever found Dolph and Macellan useful as Mercs because that's the only class, speed-wise that won't get completely raped in H5.
Gordin should also be higher than Matthis and Vyland. Still lower (if you want) but higher than those two. Those two are just horrible. The only way to make them useful is as healers. i mean, Maybe Vyland is useful slightly due to his speed but his skill is piss-poor. Gordon at least as defence to surive when you get him. The other two get mowed down in their recruiting chapter.
I also think healer should have their own tier list. You need the healing and they're not going to be doing much else. The exception is Merric and Linde, who of course will only heal if everything's under controle. They'll mainly attack. But even in Normal mode, Wrys and Lena can't cast a spell worth a shit and should stay as healers. honestly, unless you plan on giving them Bolganone or Thoron, give them a fucking Mend and let'em do their thing. If Lena and Wrys are already maxed by the time you get Maria (which they should be) then use her and don't waste the staff exp, unless you're planning on using Wendell for both Atk and Healing, in which case, still use her because Wendell won't always be available. As Melee, they also suck, so there's pretty much no arguments against this for a reclass unless you wanna waste your money of Levins and make them Swordmasters. They are amazing as Swmdmstrs--dont get me wrong, but their Mag suffers upon reclass.
One last thing, why are Julian and Rickard even classed in that? Honestly, who the fuck is using them for fighting in H5? I can see it if there's the odd enemy that NEEDS to die and they're your last option but c'mon. They should be with Est or in their own title Call it 'Should have been as funny as Matthew and Colm:'.