Probably.
I can't give exact numbers, some are variable, but I can give some numbers.
2 of 3 State Armies from Reikland + Count Rommel and Runefang
2 of 2 State Armies from Wissenland + Count Toppenheimer and Runefangs of both Wissenland and Solland (CT has been training with the Cult of Sigmar most vigorously, it is a cult that thrives on martial zealotry) + Entire Order of the Shining Talon (Knights on Murderbirds)
2 of 2 State Armies from Stirland + Countess Ava von Krieglitz and Runefang + Stirland Chapterhouses of Raven Knights and Black Guard of Morr
4 of 4 State Armies of Averland + Count Siegrich Leitdorf + Runefang + Martial Trained Heir + Stockpiled Ostland War Weaponry/Machinery
3 of 3 State Armies of Westerland
Magnus von Bildofen aka Magnus the Pious aka Magnus the Emperor aka Greatest Living Hero of the Empire and Ghal Maraz and his gryphon that has spent it's entire life benefitting from the attentions of the Magic Colleges and a Chracian elf trainer
Entire Imperial Foot, half the size of a State Army made up of finest infantry in the Empire
Entire Knights Griffon, most elite knights in the Empire personally training with and trained by and equipped by the Emperor
Entire Reiksguard, led by Reiksmarshal Fuerbach of Talabecland wielding Runefang of the Drakwald
Grand Theogonist Molatok
Arch-Lector Thorgad
Arch-Lector Kasmir
Entire Knightly Order of Knights of the Twin-Tailed Orb
Entire Knightly Order of Knights of the Hammer
Entire Knightly Order of Order of the Hammers of Sigmar
Entire Knightly Order of Knights Panther
Entire Knightly Order of Knights of Sigmar's Blood
Entire Knightly Order of the Jade Griffon
Entire Knightly Order of the Red Griffon
Entire Knightly Order of Knights of the Fiery Heart
Knights of the Divine Sword
Knights of the Cleansing Flame
Entire Knightly Order of the Order of the Black Bear
Entire Knightly Order of the Golden Lion
Entire Knightly Order of the Sacred Scythe
Entire Knightly Order of the Broken Sword
Massive Detachment of the Knights Encarmine
Entire Knightly Order of the Black Rose
Entire Knightly Order of Glinting Steel
Some thousands of Free Knights, either from very small Orders or fully Independent
Detachment of Knights Mariner
1/2 of all the Empire's White Wolves
Entire Knightly Order of the Vengeful Sun
White Flower Company Mercenaries
Quilted Chargers Mercenaries
Greatbellow's Graduates Mercenaries
The Spinebreakers Mercenaries
Silver Lions Mercenaries
Unknown Numbers of Flagellants that will come out of the woodwork
Unknown Numbers of zealot citizenry who will abandon their lives to become soldiers for this single act of Sigmarite faith
3 Monasteries of Sisters of Sigmar Warrior Nuns of extreme zealotry
Battle Wizard Detachments from all 8 Magical Colleges (Includes ALL Battle Wizards alive)
Matriarch Hildegaard of the Jade Order
Patriarch Gehenna of the Golden Order
Patriarch Caelum of the Celestial Order
Patriarch Gunther of the Amethyst Order
Wizard Detachments from all 8 Magical Colleges including Wizard Lords, Magisters, Journeymen, Apprentices
Warrior Priests of Sigmar, Ulric, Morr, Myrmidia, Verena, and Taal
8 Steam Tanks
3 Celestial Hurricanum [Celestial College Battle Altar]
2 Luminarks of Hysh [Light College Battle Altar]
1 Amethyst Mortisiary [Amethyst College Battle Altar]
1 Golden Metallus Altar [Gold College Battle Altar]
1 Arbus Vitaerus of Ghyran [Jade College Battle Altar]
2 Ignusarum of Aqshy [Bright College Battle Altar]
May have forgotten some, might need to edit later.
So, I tried to make an estimate of how many troops this all adds up to. Unfortunately, there are not enough hard numbers, so it is mostly assumptions.
tl;dr Around 500 000 men not counting Sisters of Sigmar or mercenaries.
So the way I estimated this goes roughly like this:
13 State armies plus Imperial foot being half that, with army size taken from Army of Ostland at ~ 16000 men
23,5 knightly orders with morrites from stirland counting as 1 and White wolves also counting as 1 full order at about 1100-1200+ men per order, as a rough average from the front page.
Flaggelants with 15000 from OOB of Salkalten multipled by 9. Very arbitrary number, but I assumed that if we could muster 15 000 from 1 not very Sigmarite province, The entire Cult going on a holy war can muster almost 10 times that number.
Civillian volunteers. Militia numbers at salkalten multipled by 5. Again the multiplier is very arbitrary, but I figured that there are bound to be a lot of volunteers frm all over the Empire but with 2 major crusades earlier, not as many as 10 times.
Have to apologise for the overall shoddyness, but I really don't have much to work with.