The chunky salsa rules make the game far too deadly. Most combat is done in rooms/hallways under 15m across (that's a 45 by 45 foot room, or about twice the size of a middle-high income home's living room).

Most grenades in ShadowRun will completely fill this space and reflect part of the distance back.

(God forbid an NPC tosses a grenade at the PCs standing in a 3m wide hallway!)

Of course....a simple frag grenade (not intended for breaching) will chew through 20cm of SOLID BRICK by RAW if the grenade rolls into a corner (that's before any chunky salsa effect even occurs).

I faced the same RIDICULOUSLY TOUGH (on paper) encounter with a BADLY UNDERPOWERED team. (Like....three people ~17 Karma each. My Magic 5, Agility 4, Body 4, Strength 5 Initiate Grade 1, no-bioware Adept was the most powerful party member and we were all badly exhausted (no Edge left by design) when the fight started.) Fortunately, my adept managed to get a grenade past the Blood Mage's physical barrier a split-second before it went up. Blast in a confined space took care of the rest (the barrier) and a second grenade in the water and hydrostatic shock gimped the blood mage's getaway sub. Then we picked them apart with the help of the brokezor Mystic Crusader who came with us. I know as a fact that the GM underplayed the opposition, though. If she'd gone all out with the stats as written we'd have been done-for. The opposition was very very very powerful.

I do think that in the encounter as designed however the PCs are supposed to have the element of surprise.

If I had been GMing against you and you were WINNING I would have had the Blood Mage trigger his auto-injector of K-10 and/or cast a maxed out Jaguar Form spell. Different story.