Here is the reindeer arrangement for this year:

Santa’s proclamation states that Rudolph shall lead, and the rest of the reindeer will be in two columns of four reindeer each.

Clues 3 and 4 arrange the reindeer in two L-shaped patterns:

3. Dancer shall be immediately behind Dasher, while Donder shall be on Dancer’s immediate right.

4. Vixen shall be immediately in front of Blitzen, while Prancer shall be on Vixen’s immediate left.

There are four possible ways that these L-shaped patterns can be arranged in the two columns of four reindeer each.

Clues 1 and 2 state that Cupid’s row will be in front of both Dasher’s and Comet’s rows. But these clues do not specify the relationship between Dasher’s and Comet’s rows (or rule out that Dasher and Comet could be in the same row).

Dasher is the only of these three reindeer that was mentioned in either Clues 3 or 4, so we’ll need to examine where Dasher is located in each of the above four arrangements, and see if Cupid and Comet can be positioned appropriately.

Dasher is in the front row in the first arrangement, which means that Cupid cannot be in front of Dasher.

In the second arrangement, while Cupid can now be in the first row, in front of Dasher, the only other available space is also in the front row. This means that Comet would not be behind Cupid.

Even though Dasher is in the second row in the third arrangement, there is no space left for Cupid in the front row.

The last arrangement staggers the empty slots and Dasher is not up front. This leaves a spot for Cupid in front of Dasher, and another slot for Comet to be behind Cupid. Even though Dasher and Comet are in the same row, nothing in Clues 1 and 2 precludes this possibility.