Noticed Something about Tahm Kench's Rivals

Easily seen, just about every, single yordle is a rival to Tahm Kench. However, there is one that is absent from his list of enemies that is moderately surprising for his absence. Veigar is actually not there and is not counted as a rival and I dont think Veigar would be the kind to work with Tahm Kench. So what could this mean since Riot clearly wanted to show that yordles of all kinds hated Tahm Kench and/or vice versa.