Yeah, the old hot-potato grenade trick is still viable, and still just as ridiculous as ever. It's such a gamey thing to do. I mean, it works fine in terms of balance and strategy; but it's completely bogus in terms of realism.
"Here, I primed the grenade for zero and dropped it at your feet. Now you throw it to Indiana Seasnail, and she'll throw it at the enemies."
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As an aside, it's worth noting that weapons like the mortar are in the same balance-space as grenades, in that they are long range arcing trajectory explosives.