Ships could be any shape, for utilitarian purposes, aesthetics, or some combination.
Assuming we have the goodies you suggest, doesn’t mean are opponents do; they may have left such primitive tools behind long ago.
Personally, confrontations between parties of equal technology and ability are likely to lead to stalemate; this is likely to be very costly for little affect. I hope that both parties would suspect this so all-out conflicts might be less likely. Think the cold-war that ended in the nineties.
They could start by accident of course (or by the design of individuals for personal reasons - money and power probably.), but one would hope that both sides might actually try to resolve a situation before billions of their citizens are killed.
Wars are usually fought by the desperate with inferior technology, or by the technologically superior to enforce their will for a variety of reasons and often dressed up in terms that justify their action. Sometimes their are surprises: David and Goliath scenarios do exist.
I wrote the following as a back-story for a space invaders type game I wrote using c# and xna:
“You wanted to see me, Sir?”
“Come in, Captain. We have a little problem.”
The captain felt his eyebrow rise. Air Marshal Bennett’s definition of little tended to be fatal. Succumbing to the inevitable, he spoke.
“How can I help, Sir?”
“Splendid! `Knew I wouldn’t have to ask.”
Despite himself, Blake’s lips give an involuntary twitch.
“It’s probably nothing, but there is something that needs checking out.” The Space Marshal frowns as he glances at the directional hologram on his desk. “What I’m about to explain to you must remain Top Secret; indeed, it is beyond that. But you need the information, otherwise it could have a deleterious affect on you performing the-” he paused, still frowning at his display. His normally ruddy complexion turned a pasty white.
"Well… " Shaking his head slightly he refocussed his eyes on the Captain. “Well! It would appear to be more than a little problem. As I was about to say: about half a light-year out from Sol there is a shield system. It prevents anyone or anything from passing through. With me so far?”
“Considering who you are, Sir; I presume this isn’t an elaborate hoax, so yes. I understand your words, but it’s.” His voice trailed off.
“Indeed. Putting it bluntly, half the universe is closed off to us - at least as far as we’ve explored to date.”
“It would have to be massive. Do we know who built it? Why?”
“As to who? No. I’ve a feeling the why just might be knocking at the proverbial door.”
“We have space stations monitoring parts of the shield. A mixture of curiosity, research and good old-fashioned paranoia - which, it turns out, is a good thing. It seems the shield has begun to fail. Anything on the other side can come through. Your task is to investigate sector two two three seven…”
Captain Blake felt the memory fade as the effects from the hyperdrive’s shut down played havoc with his concentration. Up until this moment he hadn’t really believed in the shield’s existence. It was too incredible. But he could see it stretching into infinity on the viewscreens; needing to physically see it he got up from his chair and walked over to the specially reinforced viewport; it was harder to see, but still there.
As he watched ripples ran up and down, relative to his position, its surface; when they had ceased it appeared to be covered in a checkered-grey mesh. Returning to his seat, he brought up the magnification on his primary display. His eyebrows rose in surprise and he felt hairs dancing on the back of his neck.
It wasn’t a grey mesh covering it. It had broken up into countless numbers of shields(?), between each was plenty of room for a good-sized cruiser. He rubbed at the ache the suddenly formed frown was causing and increased the magnification to maximum. A chill spread through his body.
He could see craft, alien craft of some weird design, waiting just the other side. Row upon row of them.
“Little problem,” he muttered to himself. “I think this just might be the biggest little problem ever.” He smiled at his own meagre attempt at gallows-humour.
He pressed a button, setting all ancillary functions to AI controll with voice backup. “Send Report,” he instructed the AI’s invisible presence.
“Sent,” came the customary curt reply.
“Lets go greet them.”
“Be sure they are hostile. I must remind you, Captain, that I have been instructed to prevent any justified claim that we opened hostilities.”
“Noted, but they sure didn’t come in peace. Even you must accept that.”
“I deal in facts, and the facts are leaning in your favour. But leaning isn’t conclusive.”
Muttering to himself again, Blake strapped in and engaged main the thrusters.
He had a planet to save…