Let's see:
Code:
pool Empire
regions forta_Province forte_Province fortf_Province fortg_Province forth_Province fortc_Province Med_Province Blood_Province Ruin_Province Laurelorn_Province Castlesreiksguard_Province Castlesigmar_Province Altdorf_Province Bogenhafen_Province Grunburg_Province Middenstag_Province Middenheim_Province Senden_Province Delberz_Province Isenbuttel_Province Fassberg_Province Talabheim_Province Lieske_Province Krugenheim_Province Volgen_Province Welleborn_Province Hergig_Province Heedenhof_Province Koerin_Province Fort_Schippel_Province Salzmund_Province Dietershafen_Province Norden_Province Wissenburg_Province Wusterburg_Province Nuln_Province Hochsleben_Province Loningbruck_Province Sylvania_Province Drakenhof_Province Templehof_Province Flensburg_Province Vorderdergen_Province Bechafen_Province Mordheim_Province Kiel_Province Nagenhof_Province Nachtdorf_Province Wolfenburg_Province Ferlangen_Province Salkalten_Province Bohsenfels_Province Lenkster_Province Grenzburg_Province Marienburg_Province
unit Gor spear exp 0 cost 840 replenish 0.05 - 0.15 max 1 initial 1 religions { chaos }
unit Gor exp 0 cost 960 replenish 0.05 - 0.15 max 1 initial 1 religions { chaos }
unit Bestigor exp 0 cost 1200 replenish 0.025 - 0.1 max 1 initial 1 religions { chaos }
unit Vampire skeleton mount exp 0 cost 0 replenish 0.05 - 0.1 max 2 initial 1 religions { vampire }
unit zombies exp 0 cost 0 replenish 0.3 - 0.4 max 5 initial 2 religions { vampire }
unit Vampire skeleton exp 0 cost 0 replenish 0.1 - 0.2 max 3 initial 1 religions { vampire }
unit Vampire skeleton archer exp 0 cost 0 replenish 0.1 - 0.2 max 3 initial 1 religions { vampire }
unit Vampire skeleton crossbow exp 0 cost 0 replenish 0.1 - 0.2 max 3 initial 1 religions { vampire }
unit Vampire skeleton spears exp 0 cost 0 replenish 0.1 - 0.2 max 3 initial 1 religions { vampire }
pool haifling
regions Moot_Province Averheim_Province Pfungzing_Province Wurtbad_Province Hornau_Province Potting_Province
unit Halfling exp 0 cost 800 replenish 0.05 - 0.15 max 1 initial 3 religions { catholic }
This is the entire descr_mercenaries.txt. If I'm reading it correctly, zombies replenish 3-4 units per 10 turns in the entire Empire, minus Stirland, compared to the 1-2 of foot skeleton troops.