Just an image explaining how to fill out a unit with squads of (mostly) equalized speed or ATK or whatever strikes your fancy.
1. Start with a blank team
2. Select the (default or left over from the old team) leader to change her
3. Set ordering to the stat you want to equalize. I usually pick either ATK or speed. In case of Nation Teams, set filter to the correct nation as well
4. Select the first available unit
5. Pick the squad leader slot from team 2
6. Select the first available unit
7. Snake your way up and down the unit screen like in the image below, each time filling it with the first available unit until you either reach the last slot, or run out of girls to add.
In the case of Whaleship crew (Can't wait till they add that!), you always want a capable team in the first (few) row(s), so you should setup those first, and then make the snake pattern on the remaining blank rows.
Nutaku: July 2016 | Flower Knight Girl: 835228859 | DMM: 646263953 飢えたハンター
Plays Flower Knight Girl, Aigis, Kamihime
Dropped Harem Heroes. Staff deleted my nice reason for not spending $.
Signature made by Myrdin
It not only isn't necessary, it makes it marginally more difficult for those who use your helper squad. The helper squad is used as-is, without excluding non-nation members. It only excludes non-nation girls from the four teams the user puts up. So keep putting your best girls in your helper squad no matter where they're from, because those who use it won't be able to have all of their best girls.
(Should also be noted that at least for now, none of this makes any difference since the maps we have now are so easy.)