Yeah. Raikou is top SR lancer at that moment I believe. (top as damaging). Jalter lily is really cute that made me love her so much, but wont help too much in gameplay besides of AOE farming. Only Artoria Lancer Alter can be comparable to Raikou.
Off course, FGO is game of 90% farming. SO Jalter Lily is still great, but she is just not your 1st priority to kill a boss.