Each person can drop 4 sectors per day. You cant drop the HQ, you have to move it before you can drop the sector its on.
Thank you for your response! I was just confused because we had taken the sector that was 2 sectors away from our HQ, which was just to the left of the enemy HQ and I thought that since their HQ was right there and also only 2 sectors away from our HQ that we could have taken their HQ as well, but I was told that we couldn't take it. Not that they didn't want to take it, but that we "couldn't" take it because it was too far away. This made no sense to me!If you hold land in an era, you can set a siege on any sector that touches one of your unbubbled or unshielded sectors, in other words, any sector of yours that you've held since before the last recalculation/reset. If you take a sector, it becomes bubbled/shielded, and you cannot take a sector that only touches that bubbled sector unless you move your HQ to it. After the next recalc, when the bubble drops, you can then take any sector it touches, regardless of where your HQ is located.
Depending on the amount of support pool your guild has, your guild might not want to take sectors that are too far away from your HQ because the more sectors you hold, the more the support pool is split. The outer "layer" of sectors 2 or 3 sectors away in any direction gets the least support bonus if there isn't enough support pool available for a full bonus for all sectors you hold. So, this might also be a reason you were advised not to take a sector further away from your HQ.