So first of all, its nice that i did get pretty objective replies. In my answer I still wouldn't quote and answer to each single thing said, and would rather write it general.
I do have played a few speedruns, I believe we had a rank 1 in blight, king of giants, ascension and passage to darkness, end of the raven and empire, and siege of hope ofc. Monstly I played it one month cause, back then you needed some rank 1 to get the xp for the higher pve rank. Not sure about bad harvest, I believe i played a few games as a feeder in 2009 not sure, if it ended up in a rank, additionaly i did play it 2 times in the carry position but to make it through without dying once I believe I would have had to played it 4-5 times at least, not sure.
On blight I had the carry position and on king of giants I stayed t1, on the empire and end of raven I didnt do much. On all the maps I did not develop any strategies, maybe on blight a bit, because its next to passage to darkness and ascension map 3 the only maps i do sometimes play.
As you know I mostly play battelground and I had forgotten about decomposer. But even on battleground I realized if someone has a better time, the person, usually uses a different strategy or deck. You can play the map in a hard or use some speedruns meta deck which usually is pretty easy, but for the last minute it gets a bit difficult.
Back then lost spirit ships were meta. Like I said before with wheels or stoneshell, you basically you dont have to look at the monitor to clear the map. But if you play them with motivate, and no defensive spells just more damage spells, then it gets a little tricky, if you have to direct the skyelf additionally and defend somewhere else too.
One of the last speedruns that I did play was lvl 10 solo. I believe I had 25mins with ships in the speedrunway played, then I tried the green batariel, whichwere like about 25 mins too, and without wheels you had to look out for him a bit. Then I tried the black batariel with frenetics, which took then 20 mins, and it was pretty relaxing to play. Then I did look at Treims replay so when I switched the red start to black, it were about 18 mins, I still missed some cardes like nether warp green and 1 other. Then it would have started to get a bit tricky when you have to work with 2 batariels at the same time on the map it gets a little harder.
In the campaigns even if you only have your t1, you still have to do your job and focus in a speedrun. Its just not the same complexity as on a carry position in a speedrun.
Right now its a bit sad that even in battlegrounds you dont play the map in its usually way, but warp over get the t3 fast, maybe 1-2 players feed. As a battleground player this is a little sad.
But to summarize, when I do play with people in lvl 10 that have high ranks in campaigns or even battleground nowadays, they pretty often do not play well. Im happy if they have a basic understanding of how a lvl 10 works, and when im lucky they can adapt to the situation that occurs.
They usually play better then just random unknown players, but not as some unranked players who play battlegrounds more often. Personally the way I play the lvl 10 is that everyone get their t2 alone and you only help if someone needs it. Also you take the t3 alone or together, no orb give ways. The orb giveaway make it easier but takes the fun out of it. If you played a map a bunch of times and then you see it with speedrun techniques its pretty painful to watch.
To summarize it again, in a speedrun where you only get t1 you still have to focus, but its easier then when you would have to play till t4. Aditionally some cards just make the game easy, which are usually t4, or with ami or enlightment t3. Without ami and enlightment, to clear a map with just t3, or just t2 is a lot harder. And if you can skip those its easier but again its takes less skill.
Would put it this way:
Imagine there was a battleforge, the same as this one only there is a t1 card for 50 energy which kills all opposing structures and units. Then basically all would think this card should be nerved except maybe the one person with the best computer, you was able to use it first and get all the rank 1s.
Then the card get neves to t2. Still people think the card is too good. But now there are already a bunch of people who perfected their t1 and think the card is fine, and they put work into how to get to the t2 the fastest. To the onces who woud like the map to be played till t4, and in a way the game is played usual they say, this is speedrunning, if someone doesnt like it they should play casual.
If the card get reworked to t3, then there is t1, t2 to play and a bunch more people will like it to stay because you can use more techniques to get to the t3 fast.
Right now, you basically skip the t3 with enlightment and amii. And you skip the t2 if possible with nether warp. Its fine but makes the map a lot easier. And if you are someone who plays the maps from t1 to t4, and people are suprised about the good times that some people achive, its awkward.
Ok, as a last summary, if you want to play with me randoms lvl 10, and you have a good speedrun time somewhere then its a good start, and we can work with that, but there is a pretty long way to go.
Additionally it would be nice to see the times of players who played the maps in the usual way, and to see in which time they can do it. And then compare your own times to them.