I am sure Rocky or someone else can give you a better answer, but let’s say the total pool to go to the payouts was $22,160. So in the case of #3 there would be 10 tickets for $22,160, which would be a will pay of $2216, while in the case of #4 there would be 20 live tickets with a will pay of $1108 (I rounded for the sake of the simplicity).
#3 = $2216 = 10 tickets (10 x 2216 = $22,160)
#4 = $1108 = 20 tickets (20 x 1108 = $22,160)
With the dead heat, you would have 30 live tickets taking a piece of the $22,160, so that would be less money on the payout ($22,160 / 30 tickets = $738 each). The actual total pool was about 10 times this amount as were the number of tickets, but in this watered down example, you can easily see how the payout should be less than the original two will pays.