The best place to train in general would be the Sunny Grasslands. And also I noticed on jado's body he had the five element divided on his body or something. His big hand was water, and his face/chest was fire.
We make our friends; we make our enemies; but God makes our next-door neighbour.
Well, the best place that most would recommend at that point is Wyterra with the lv 50-51 Krawl running around Dawn Bridge, Sunny Grassland and Valley of Mist. Or you can do the easy way and just excavate your team, other than the card-only ones, with A rank so they'll be at the lvl you are should you be lv 75 or higher [like me whose around lv 84 from excessive training for the dang Fire Ruins boss]
i tested my thoguhts of element-forcing, agiasnt y'alls of dawn-mist areas only
however my conclusion you wont like You guys are doing it easy-but-long-way, but not the effective-hard-and-short-way
: Easy way is to fight the dawn-mist area on wyterra's Gris-style Krawl, however they knock you around, A LOT, dealling heavy damage
now the hard, but more effective and shorter way i took my level 50 Flamerax to Doldogo and fought a couple of waves of Swar-style krawl firstwave being 3-count swar and next being 5-count of swar, i counted the EXP, and on doldgo i got nearly 2x as much as dawn-mist areas gave in one run to the final river-beach and back, i gain 1 whole level and TONS of minerals,
i repeated this per element, turns out, Wyterra is easier, but the elemental planets give tons more EXP
BUT, yes there is a catch On salyso, there are mostly Sky and plant krawl, Butosbasu would level up fast fighting sky based krawl but get hurt fighting slayso's def-based plant krawl thsi pattern repeats: Doldogo has most-plant, few-water Slayso, as above has most-sky, few plant Menahat has most-earth, few-fire Kogoeria has most-water, few earth and Bahmud has most-fire, few sky ---this is set up so you will in-gamely have a hard time, but it's overcomeable, by equipping a weapon that defeats the few-typed krawl
ie: On Kogoeria, train a sky-spectrobe but equip the spika-axe or Pepe Sword for wehn the rare-and-few earth types show up, and do so respective-elemently per planet
---respectively repeat, and you and you team wll level up ASAP
Hokni De Iku Ze! i am a major Spectrobes fan, it's my fave game