A Sicherman* Dice variant could be a way of twisting the two player experience a few degrees. Remove two regular dice and replace with a pair of Sicherman dice.
Substitute the following play area for your vegetables:
You would be able to take the face value of any die and place it in a valid space (ie: a 4 is possible to be rolled on any of the dice and can be played in any of the three rows.)
This twist will have the benefit of changing the placement of vegetables, feed the pig more often, and rely on the 8 roll to finish out all three rows as an end game condition.
It would need to be tested if the Pig Power to plus/minus the number on the die would be able to go from 6 to 8 (and the reverse). Is one value appropriate to go from 6 to 8 only on a large die?
For a two player game you would still use 6 total dice, 2 of each color and now also two of each size. The player with the first player token makes this choice prior to rolling.
Considering the two player game there are now more choices to be made (6 ways to roll) with all of the above still being true for the game.
What do you think?
*Sicherman Dice are a pair of 6 sided dice that when rolled provide the same outcome as a pair of regular dice, except the numbers on each side do not have the same distribution.