For 6th how mandatory are skaven slaves, especially for a skryre focused list? Any list building recommendations for a 2k list? I'm not looking to be competitive I'm just looking to have fun.

For reference I currently have 2 units of clanrats at around 25 minis each, both with a weapons team. I have 3 jezzails and I plan on getting a couple engineers. I also have a grey seer. For a 2k list should I take skryre or warlord, and should I make the grey seer my lord or the other choice?

Thanks in advance