I was in a table of 7, 5 pregens (we doubled on the investigator) a lvl 2 hafling monk (with a full wand of CLW) and lvl 3 dwarf Rogue. We suffered no party deaths (although we had characters go Negative 3 times). I will admit would not like to go through this w/ just 4 characters and just the 4 pregens, we would have been slaughtered with the scenario as written.
We were also lucky that we decided to bypass the obelisk room and never got to the harem or the boats, (we were in hour 7 and the GM decided to call it after we defeated the mummy & pet) which would have burned through a lot of our consumable resources. In fighting the big boss, we all pretended to sacrifice one of the investigators (me) in fire so that we could get close enough to accurately throw alchemist's fire on the mummy, except the warpriest who used the searing light scroll, and hit the mummy w/ 6D6 of fire, all of us rolled well above average, and the searing light. It was enough to put him down in 1 round.
I also wanted to raise the concern about the investigator's inability to do any damage in 2 of the combats. Even the swashbuckler (with the application of pinache) had the possibility of doing some damage against the pyramid and the Anubis statues, not much, but something The Warpriest and bloodrager are capable of hitting for 9+ damage most of the time. However, absent a confirmed Critical, there was no way that the Investigator could do any damage and nothing to do except use the CLW to keep people up. Now I don't mind that role when I am playing my own character. If I didn't plan for that contingency, my fault, I make the best of it. But with a Pregen, where your spells are picked for you, you expect that the spell will have a purpose or at least not be totally useless. As it stood, the stone fist spell was of no more use than the club already provided, because it could not bypass the hardness. Somebody really needs to either errata the spell (bypass hardness of 8 OR less or the hardness bypass scales ie bypass 5 + level hardness) or change the scenario description (Hardness of the objects of 7.99)