Now I'm sure some of you are sick of RtCW veterans whining about how stock ET classes and maps are badly balanced, but comparing the two games yields important insights into this issue.
You can trace this consternation over rambo medics all the back to the initial ET release. We were the first to notice and complain during the fueldump only beta. ET medics simply have too much ammo and can operate independently of field ops.
The reverse is true too. RtCW Lieutenants (field ops) have to constantly ration their charge bar to supply ammo to medics. ET field ops have far more charge to use for artillery/airstrike. This is made less problematic in ET with the introduction of sticky charges and a team-wide recharge timer artillery/airstrike. Additionally, ET airstrikes have their charge requirement increased from 1/2 (in RTCW) to 3/4 or full. These changes had not been necessary in RtCW despite how easy it was to spam airstrikes.
One simple change (in the sense of gameplay complexity) is to deny medics the extra clip + grenade after leveling light weapons, and the ability to pick up an enemy's dropped gun. To get a sense of how much difference this makes, watch how differently Caro plays when he limits himself to a single pistol as primary. This is how gunfights in RtCW often end up - 'orphaned' medics have to fend for themselves with the miserly pistol against SMGs that fire 2-3x the ET rate (see this). In RtCW, I would run around with the pistol and only switching to SMG when necessary to conserve ammo. In ET public games, I'll often go full on rambo and self-kill unless my team is under siege.
Another factor that incentivises rambo medics is map design: the availability of ammo cabinets, and placement of spawn points. The latter point is subtle. In the standard maps, spawn points are often close to objectives in such a way that it's relatively advantageous to go on a solo shooting spree and then self kill. Think of tc_base vs erdenburg.
In tc_base, although both radars are relatively close by, reaching them opens yourself up to easy attacks.
To reach the north radar, you have to thread on open ground surrounded on all sides, high and low.
To reach the south radar, you have to run through a narrow corridor which enemies have a clear sight of and then clear one of two narrow gaps (one of which requires a jump) to access the staircase.
So when the south radar is lost, Axis defenders tend to prefer holding their position on the high ground, or staying near the spawn to watch the ground corridors in both directions. It plays out this way in both public games and tournaments unless Axis is dominating.
You can make a similar point for the others: Village, Assault, Ice, Beach. There is little you can do to address without architectural modifications, except maybe to remove ammo and health cabinets. It sounds like overkill, however.