From my experience, in 3.5k you can't particularly rely on your teammates to punish greedy lineups (because in all honesty 3.5k players, myself included, aren't particularly good at the game as a whole). I personally play on the assumption that my team won't be proactive, so I'm probably going to be the only one to get things done. Now of course this is not always true, in fact the assumption is probably going to be wrong more often than not. The thing is that there is no downside if there are other proactive members on your team. The thing is, that if they aren't, then you are probably fucked.
So if you're really looking to win these games, idealistically if you can't rely on your solo queue teammates to be reliable, then you want to be picking a core that scales well and can take objectives on their own (which seems to be what you're doing). That is, heroes that are able to fight in the midgame and are still relevant if the game does go late, take towers (potentially on your own), push out lanes/control the map and contest the enemy carry(s) farm.
Another big thing is to make your best efforts to communicate with your teammates. Try and make it clear to your team that their team is clearly playing a greedy line up and that it will be an "easy game" if you try and take objectives/map control and punish the enemy for their greedy picks.
Based solely on the dotabuff match info, I'm going to comment on what I think was going on (can't really load up the replays or anything at uni).
So, lets look at this in the context of the tiny/sven game. Sven supposedly free farmed for 20 mins. At the very least he should have around 150lh at this point and create pressure on the map by pushing his lane in (of course, hitting the towers in the process). Considering that he only has 250lh 45 minutes in (implying that over the rest of the game he secured 100lh/25 minutes) and that his tower damage totals at 404 (aka not found), I would say he did a pretty awful job on that. On top of that he would've fed any sort of lead he gave your team through his free farm (while I'd assume the rest of you were making space) through dying 6 times. Do you think the game might have gone better if you were playing in svens position instead? (Anyway sorry if any of what I said is redundant here I just realised your were the tiny and not the viper). Anyway there wasn't much you could do against the snowballing slark. However would you say you accomplished much with the shadowblade? You only had 3 kills (as someone with a lot of kill potential). I would say that the item probably wasn't warranted. Personally, knowing that solely by looking at the lineups that your team had the better late game, I probably would've been more greedy with my item progression. Is drums also worth getting on tiny? It seems to be a pretty bad item on core heroes. The only reason I could see you getting it is for tiny's mana issues, which you could fix with a silver edge (tiny being potentially the only hero on which this item is actually good on). It would've also greatly increased your kill potential because of the additional burst it offers, and would help you farm a bit faster when your aghs was online (and costs about 2000 less than shadowblade+drums and has a pretty decent build up).
Okay I think I'm going on a bit to much here so I'm going to have a look at the sf game now. I think your team was very much on a timer there (as you probably knew) so I think it would have been crucial to communicate with your team and try and punish them as best you can. First of all I think aghs is appalling on sf, even after the changes. It only really offers you something if your ahead. The moment you fall behind it you'll have to spend time trying to get your souls back, usually in a situation in which you'll be forced to fight without them. Given that they were smart enough to buy detection, it would've been very hard to actually get a successful ult off that fight with the amount of disable they had with shadow shaman (and searing chains) and the fact that ursa could pose a big threat during the channeling time, especially with a bkb. I definitely think you should've upgraded your shadowblade to silver edge, as the debuff would greatly neuter ursa and juggernaut's damage output. Your team might've also greatly benefited from a mek (as neither the bh or the rubick built one) which would've helped you fight early/mid game. Anyway it's important to note that with those cores they would've been either all over the place to secure farm (and as a result easy to gank with your team) or all huddled up and getting very little farm (in which case you would want to force fights while they're all small). It's also important to note that your team was all pretty squishy and easy to kill with shadow shaman + 1.
Anyway there's not much else I can personally add since I'm also just some 3.5k scrub. Hope this was helpful in some way. If anyone wants to point out something is said wrong please do so I can improve my own understanding of the game.