I never really played CnC, was basing my thoughts mostly on WoW. Not sure how default targetting in wc3 worked, but from memory something like "attack whatever is first in sight, but switch target if somebody else damages me more". It does have special spells like "taunt" that are used by tanks to get enemies to attack them, even preventing micro from interfering.
@ZaphodX how about: -vanguard buff by 1 speed and slight cost decrease. -grenadier buff by cost decrease to 80 (real buff to numbers), and if more is needed buff damage by 1/5 and Nerf rof by 1/5. -naval needs teleporter, price decreases, some damage range speed buffs -catapult range made to 350. Pelter given 320 range. Pelter rof increased to .25. Catapult rof increases to .35. Pelter damage is made 200. Catapult damage made 1000. Catapult good vs t2, pelter vs t1, due to overkill and price. Both can actually reach then without being just 2 range lengths away from tanks.
I honestly feel like the vanguard has it's own role. I find it works great against T1 blobs because its splash damage is enough to kill most T1 units (I'm pretty sure at least) and it has enough health to soak up lots of damage for your unit blob. Mixing vanguards into a T1/T2 army, or using them against a T1 army has worked pretty well for me so far...
I find infernos are much better at doing high DPS against structures and defences, whereas vanguards are better against armies.
I still believe in my crazy idea of making the Vanguard a semi-combat-commander. In T1 you can use your commander as a frontline combat unit but by the time T2 rolls out the commander is too weak to take the risk. Instead, let the Vanguard play that role. Since its weapon already looks like a Uber cannon make it behave like a Uber cannon: same range, same damage, same energy use, same building damage debuff. Then also give the Vanguard the same speed as a Commander. Now you have a tough, splashy, anti-unit unit that's no good against bases.
They are completely different weapons right now, basically just sharing the same effect. Commander Uber Cannon: Range: 100 0.2/s fire rate Splash: 700 damage, radius 20 Uses a relatively small amount of energy to fire (stupid) 75% damage reduction to structures and other commanders Vanguard cannon: Range: 30 0.5/s fire rate Splash: 2000 damage, radius 10 They need to be made more similar or be given different effects.
I find the Vanguard to be quite an important part of a T2 tank army. It provides the sort of rolling front line you need for your mighty mortar tanks to belch shells at the enemy without fear. I set my T2 vehicle factories to spitting out a 1:1:1 ratio of Levelers/Vanguards/Mortars for a reason.