Irysa

If Shanna is undertrained then you are strategically limited in many scenarios and she'll probably perform poorly against most enemies later. She already needs to be handled with relative care and also likes having her sword rank raised.

I have to be honest dude, I think you should just play the game and think about replaying if you felt things were too easy or too hard or whatever.

Bartre doesnt need to be alive. he extra energy ring is from saving the civilians in his map. Lilina's speed is bad but neither her nor Lugh actually double most enemies unless you grind Lugh a lot so she hits harder per hit. And yes, like I said, you go to Sacae is your Nomads are trained more than your Pegs, you don't just get to pick between them.

The gaiden maps are a mixed bag. 8x and 12x are both okay, nothing amazing, 14x and 16x are pretty good and interesting, 20X for both routes kinda sucks and 21X sucks.

Not screwed beyond redemption but definitely screwed out of being a major contributor later in the game. Looks like you'll have to rely on Percival more. A mage helps depending on how slow you're going, like I said before. If you go slower then a mage will be able to make more contributions. I'm slightly partial to Lilina since Lugh doesn't really double all that reliably anyway so Lilina's harder hitting is nice.

If you don't know how to do it then you should just look at the site's guide on it.

https://serenesforest.net/binding-blade/miscellaneous/gaiden-chapters/

7 str at level 17 sounds horrifically screwed lol. Thats like nearly -5 on average strength.

Igrene is useful in Sacae because the majority of enemies are dodgy nomads, so if you want to be able to fight them on Enemy Phase then Bow users are the best bet due to how inaccurate Javelins and Handaxes are. Sue isn't terribly durable so another unit that you can rely on helps.

Warp isn't that complicated, it's just a staff you can find in the desert map (chapter 14), you may want to look at a guide so you dont miss it. It allows you to transport an allied unit around, and this can be used to avoid certain parts of the map or whatever. Saul can make some good use of it, but Niime's high mag makes her a better user of it lategame. If you don't know how to Warpskip you'll probably have a lot more trouble with some of the later maps with less units, part of the reason why they're not too bad with a smaller team is because of Warp.

I'm afraid the way you've prased the question is confusing me a bit though since I'm not sure if you're asking for unit advice to make the game easier or make it harder or if you want to cut more units or not. So here are suggestions both ways. The first point I'd make is that going to Sacae in itself will cause problems, as Shanna will typically be maintaining a level lead over Sue if you are using her a lot, and Sue doesn't gain EXP at a terribly fast rate due to being a Bow user. So you'd have to sandbag Shanna (will really hurt you later), or slow down a lot to make sure Sue wins out.

I would suggest considering going Bartre route for the extra Energy Ring as both Lance and Shanna appreciate it a lot.

Depending on how slow you're playing you may value training a Mage of some kind, so Lugh, Lilina or Ray are options to consider. This sort of simulteanously makes the midgame a bit harder since you're training a frail unit but if you train long enough you get some useful benefits and units with defined niches.

Echidna, Igrene and Bartre are all solid filler prepromotes without HM bonuses, Yodel is obviously handly too for lategame Staff stuff. They can all easily slot in and out as you need. If you are going to Sacae then seriously consider deploying Igrene

For units to consider cutting; Clarine kinda falls off after you get Cecilia. Astore's combat is pretty lacklustre against Sword or Lance users, or just promoted enemies in general, so he doesn't really need to be deployed in maps where you're not using theif utility.

I would say a solid FE6 team needs 5 primary components which you've already fufilled;

1. Competant flier - Shanna w/lots of investment and boosters

2. Competant paladin - Lance w/lots of investment. A second competant Paladin is very nice but not as important, Marcus and Zealot fill this role fine for most of the game then Perceval picks up the slack.

3. Competant bow user, prefferably mounted - Sue, if going to Sacae then Igrene is very much valued.

4. At least 2 competant staffers, 3 or 4 for lategame - Saul, Clarine/Cecilia, Niime, Yodel

5. Competant bosskiller. This one is shaky since Dieck is basically just "okay". He has all the attributes that make him good at it except being fast enough to double. He got really speed blessed in my run and managed to be a lot better at it than he should be. However the alternatives aren't that great; Energy Ring Lance isn't really much better than Speedwings Dieck and there isn't really much demand for Speedwings on your team besides possibly Igrene or Percival. If you really want to cut units, you can consider cutting Dieck and trying to just have Lance be your bosskiller.

Oh my god I hate this comment system. I'll PM you the full thing instead.

http://irysan.tumblr.com/

I don't really use it anymore because I want to engage with people when I have ideas or thoughts about things instead of just having solitary musings. Well the latter is fine too sometimes but it's still prefferable to talk to people, and it's also somewhat more effort to make high effort blogposts than it is to have a conversation with someone. I had a brief stint of writing articles about game design on a different website (that I'm not g...

I'm still waiting for Risen to leave the tonic shop so I can buy str tonics for Lon'qu lol

Oh yeah, I just felt like something different. I'm actually doing chapter 12 of 11 right now.