Frankly, paper card legality likely wont be a concern for for some time, and if this problem does arise, Magic has time to respond
While trample doesnt technically make a creature unblockable, it does change the math on blocking enough that tramplers will often deal their full damage to players as if they werent blocked
On top of greens already solid ramp, there are lots of cards like Marwyn, the Nurturer, Gyre Sage and Rishkar, Peema Renegade that work with this theme specifically to make dizzying amounts of mana
Dead Weight just seems like it is less effective against the range of 3 and lower CMC dorks and also significantly less useful against the bigger things
When Hostage Taker enters the battlefield, exile another target creature or artifact until Hostage Taker leaves the battlefield
We'd all rather draw in most situations than force discards