So you rather believe all trioxin uncroaked are same strenght? Than is your right.
If they weren't, there'd be little incentive not to just use trioxin all the time. If a mass uncroaking can uncroak a warlord AS a warlord along with dozens of additional troops vs. just uncroaking the warlord, then it's a no-brainer (heh. zombie joke.) to always use trioxin. The advantage of having them last longer seems relatively underpowered suddenly, unless they're both tougher AND longer lasting.
Trioxin uncroaked are just regular uncroaked, and the strip makes that very clear.
Eh, trioxin makes the "weakest type" of uncroaked. This can mean either (a) lowest absolute strength, or (b) lowest percentage of original strength. Note that (b) would mean that higher level units, when killed and trioxin-uncroaked, are still stronger than their fellow trioxin-uncroaked grunt troops.
Again, to clarify:
Croakamancer spends more time, unit is 'x' strength.
Croakamancer uses trioxin, unit is 'x - 2' strength.
Croakamancer uses more time, unit is 75% of the strength it had when it died.
Croakamancer uses trioxin, unit is 25% of the strength it had when it died (warlord abilities may or may not be retained).
Either (a) or (b) makes sense in light of the strip about trioxin, but I think that (b) is more consistent with normal croakamancy skills; ie, stronger units make for stronger uncroaked, generally speaking.