Alternative Games?

Ok first of all I have to say: instead of restarting you could just keep playing on one account and level up your units. Then you migh have better chances at winning, don't you think? If you just stop at level 8, of course you will be always underleveled.

Now for your actual question. If you want a strategy game in the style of a mobile game, then sorry, but I believe there are none. The only one that comes close to that is "Boom Beach", it's a free game, but it's like Clash of Clans: it takes very long to get something done later in the game. It has base building and you (sort of) micro your units to attack and destroy enemy base. Basically you build up your base + defenses, and enemy tries to attack and destroy it and vice versa. Played it for a bit, seemed alright.

If you want games that are the same, why not play the older C&C titles? On Origin (I know Origin is bad, I installed it only to buy 1 thing) you can get the "C&C Ultimate Collection", it contains all the previous C&C games for only about 15€, very cheap. If you want to play some oldschool C&C, this is the way to go.

If you want to play against other players you have to get a game which is still played online. The only one I can think of is Starcraft 2. All others are mostly singleplayer because they are too old.

If you don't care about multiplayer/graphics and coop/campaign is enough for you, I can recommend 2 games: "Dawn of War Dark Crusade" and "Earth 2150". Played both games when I was little and really enjoyed them. Both are RTS games with base building. Both can be bought on steam. In Dark Crusade you can have giant battles with a total of 7 factions. In Earth 2150 (NOT 2160, 2160 was only "ok") you can design your own units: you research technology (for example rocket launcher) and then you can put it on a chassis. 

Can't think of anything else right now. But srsly, either play on one accout longer, or check out Boom Beach if you want a mobile game, or check out "Dark Crusade" or "Earth 2150".