Personally, I would advise against doing so. Contrary to popular belief, Smith & Wesson didn't include those springs for the sole purpose of making the trigger heavier as part of some agreement with Glock which only exists within the realms of Internet Urban Legend.
Both of those little springs are return springs, one of them is merely to reset the trigger safety and really doesn't make much of a difference to the overall pull, so removing it doesn't really reduce the weight of the pull and is potentially dangerous as it allows the trigger safety to disengage with simple momentum/gravity. The other spring is the trigger reset spring which is where most of the weight comes from, but is more important that you might think. Without the trigger return spring in place, the trigger/sear can potentially fail to reset when firing full-power heavyweight ammunition as the recoil impulse holds the trigger in a reward position.
Folks who prefer lightweight standard pressure 115gr 9mm Luger, 155gr .40 S&W, or don't actually train with anything but target loads at the range are unlikely to ever encounter this issue, hence why so many folks swear by removing/replacing the springs in the trigger with no reservations whatsoever.
However, if you plan on shooting heavier loads like 124gr-147gr 9mm Luger +P or 180gr .40 S&W (depending on what your Sigma is chambered in) then it's not recommended, especially if your Sigma is a .40cal SW40/SD40 model, as the issue is most common with .40 S&W.
Personally, as someone who carries a SW40VE as a primary carry gun, I left my pistol in it's stock configuration for the sake of reliability. A long, heavy trigger pull can be overcome with training, and frankly the oh-so-heavy 8lb-12lb DA Trigger on the Sigma Series of pistols isn't all that different from a stock DA Trigger on a S&W Revolver, which police carried for the better part of a century without any trouble. Folks these days are just spoiled by the lightweight SA Trigger of the 1911 or short, precocked DA Trigger of Glocks, and tend to arbitrarily label heavier triggers as absolutely impossible to shoot accurately with as a scapegoat for their own lack of finger strength/skill. Besides, that trigger pull is going to feel much lighter in the event in which your body is flooded with adrenaline in a life-or-death scenario.
That being said, if your Sigma is mostly going to be a range piece (why?) or if it's a SW9/SD9 which you plan to load with standard pressure 115gr 9mm Luger ammo, then you can go right ahead and replace the trigger return spring with a lighter aftermarket spring, and it most likely won't cause you any trouble whatsoever, but don't outright remove either of the springs if you intend on using it for Self-Defense, regardless of how many folks may come along swearing it's perfectly safe and won't effect reliability whatsoever.