Short version: Has anyone switched their team of warrior.healer.3xmages to paly tank? or replaced a mage with a warlock? or both? Looking for advice from you!

I am 36 with my team, currently Warrior+Priest+3Mages. The group can get it done for sure. I am progressing through SM and its all good.. BUT! I have to port back to SS when my bags are full and or I need to repair. I'm guessing this will always be an issue got forward. SM is a little more punishing for this due to it being in a horde zone. I hate the long run there! Just not sure if that is a reason to switch up my team ( adding a warlock for summons extra utility)

Another issue has been discussed a lot. The AoE threat of the tank. I can make it work, but it takes a time and a lot of work to make it happen. I cant pull too big of packs or someone always dies ( i only attempt large pack when the mobs are green to me ) I am getting better at it though. My question to those of you who have switched from warrior to prot paly tank. Is the aoe threat much easier to maintain? would it be worth it to PL a paly to replace my prot warrior? I'm mostly interested in advice from anyone who has actually made this change in their team. I know a lot of people were talking about adding locks for eye pulling/summons and paly tanks for better aoe threat.