Not for 1v1 it isn't. You foget that doc has demos, which if used early can really devastate the enemy. If push comes to shove you also have cheap armor at your disposale with the m10, which is just a little worse off p4 for only 80 fuel. The off-map is great because it fires huge railway arty type rounds off in a big AOE so if the enemy thinks hes safe on one side he needs to think again. Calling in one bulldozer sherman is great for countering people who tend to blob. Airborne imo is actually the worst doc for 1v1 as the only really good thing going for it is the lmg upgrade for airborne. Everything is overpriced for stuff you can easily get cheaper and crewed for 270/280 mp in t2/t3. In fact I've used Armor'd doc every time for each of my 1v1s to get to the rank of #1 USA. MVGame
I agree, armor allows you to go either T 2 or 3 and tech to T4 and have a decent med anti armor unit. I have been going quick t2 for a m20 with mgs to gain map control and mining choke points with the m20 to kill light armor or stall medium armor and then teching to t4 for either a m80 or Sherman to assist in anti okw blob control. The m10 comes in when I need some AT. The Sherman or m80 coupled with the Sherman dozer allows you to do great squad wipes on inf okw units and the Sherman/Sherman dozer can serve as meat sponges and both have smoke to mask them for AT fire while the m10 gets on the flank of the offender to get the side and rear shots. If the m10 fails or you can't handle the heavy armor you already have T4 and just save for a Jackson and fight conservatively till you get one. If you pull it off you will have 1x M20, 1x M80 or 1x Sherman or 1x Sherman dozer and 1x M10 plus your Jackson more than enough armor handle enemy armor along with your 3 to 4 rifle squads and mgs.
Another option is instead of going for T2 go for T3 for a Stuart and calling in the m10 to work the AT role. Tag teaming the Stuart with it's stun shots and the m10 works well. With this you can build AT guns to augment the m10 or hold the line till you get the m10 out and call in Sherman dozers for anti inf or go to t4 for Jackson's or Shermans.
Assault engs I find are very useful especially on city maps. You can have them wire off approaches early along with the rear echelon sqd to stall your opponent, upgrade to flamers to help clear out garrisons and lay demo traps. Demos are extremely effective on city maps where the streets with buildings force the opponent down them like a funnel just asking for the demo saying detonate me.... It makes my day watching a OKW player loose a chunk of his blob to single demo. They also do a huge amount of damage to armor I had one knock a KT down past 50% hp.
The M10 could be a little quicker but once you get it to vet 2 it gets really useful with its access to advance AP rounds and Flank speed at vet 2 it's a great asset. Even then you can always have the crew bail before the bitter end and have them crew a Jackson or Sherman type tank.