There have been a couple threads where alternatives to AR have been mentioned (Soldier's Fury, Flail etc.) but in the end, AR is still voted as the best IAS for a Paragon.
Since the Imbagon is the most popular build among players, I'll use it as an example:
[build prof=paragon/warrior name="good imbagon" spear mastery=11+2+1 leadership=11+1 command=8+1][spear of lightning][go for the eyes][save yourselves!][there's nothing to fear!][anthem of flame][aggressive refrain][focused anger][for great justice!][/build]
This setup works okay. To maintain AR, use Anthem of Flame/Weariness in between fights and GftE during the fight. The only problem is that GftE takes away adrenaline that should be going towards SY, creating a hiccup.
[build prof=paragon/warrior name="better imbagon" spear mastery=11+2+1 leadership=11+1 command=8+1][spear of lightning][save yourselves!][there's nothing to fear!][aggressive refrain][focused anger][for great justice!][optional][optional][/build] pve-only options: [pain inverter][technobabble][ebon battle standard of honor][finish him][you move like a dwarf!]
Cut the crap and use TNtF to maintain Aggressive Refrain. By doing so, all your adrenaline is going towards SY and it opens up 2 more slots. At 12 leadership, there's a one second window to use the shout. If you're amazing, you can pull it off...but I'm not so I cheat

THE HELMET SWAP
Go to Kamadan and buy the cheapest Leadership helm you can get. Then slap a superior Leadership Rune on it. When you first load a level, swap your normal helm with the cheap leadership one. Cast Aggressive Refrain. It will now last for 25 seconds, giving you a larger window to use TNtF. Use the shout and switch back to your other helm. To help with energy, keep a staff in one of your weapon slots.
Hopefully this helps!
*Note: I know this is probably old news to most players, but just tryin' to help
