Don't noob around with orc mods.
Use the new features. In your case, up the cavern difficulty in world generation, or just try new embarks. It's a flat-out lie that the new underground is generally not very dangerous. As with everything, worldgen caverns are set to "newb" settings to prevent driving new and/or incompetent players more crazy.
Lastly: if you found the orcs or anything else --modded or otherwise-- in the last version to be truly difficult, you've got problems. Orcs were pitiful compared to a well-trained and outfitted dwarf. Only now do you actually need to take threats seriously, with the new combat modeling and injury modeling. You don't need to be sieged by 20-70 orcs right on embark to be in danger. A half-dozen goblins are more dangerous to your difficult-to-train normal troops now than 70 orcs to 2 (easily attained) champions in the last version.
You're just making an appeal to nostalgia. One that's very out-of-place, in my opinion. Rushing yourself with enemies at early stages was the worst, most half-assed way to add difficulty imaginable. It's on par with ruining an RPG for yourself by grinding. The only reason we did it is that we lacked the ability to fix the combat system --which Toady has now done.