Since you want to choose a poem, of course, you should try to fit the theme. This is in tune with the theme and the words are well written. If you choose two calligraphy works of the same level, it will definitely be an award that fits the theme.
For example, in the calligraphy contest commemorating the anniversary of the Red Army's Long March, the judges will vote for the first one, even if the latter one is slightly higher than the previous one.
If it is a calligraphy competition to commemorate the anniversary of Li Bai Rugan, then both Li Bai's poems and poems praising Li Bai are in line with the theme and are more likely to win prizes.